The following vendors each supply interface units and sensors.
Data Harvest Educational EasySense Flash Logger

http://www.dataharvest.com/Products/easysense/flash.htm
Specifications:
The EasySense Flash card logger slips solidly into the Compact Flash expansion slot of your Pocket PC to form a completely integrated probe solution. Everything your students need to record and analyze data can be easily held in the palm of their hand.
Despite the low cost and small size, The EasySense Flash system offers the same functionality and ease-of-use as a full PC based system. Graphs, charts and tables appear crystal clear and setting up experiments and analyzing data using The Pocket PC's touch screen technology is a dream.
The EasySense Flash Logger accepts the full Range of SmartQ Sensors (http://www.dataharvest.com/Products/easysense/smartq_features.htm) and automatically identities and calibrates them!
EasySense Flash simultaneously records and displays readings from three SmartQ sensors.
EasySense Q Advanced

http://www.data-harvest.co.uk/datalogging/esqadv_g.html
Specifications:
LCD Display – 4 x 20 character
6 Sensor inputs (analogue and digital)
Analogue resolution (ADC) 12 bit/1mV
Fastest sampling speed 20µs (50kHz)
Auto identifies Smart Q sensors
Auto calibrates Smart Q sensors
Firmware upgradeable
Memory 2M
External power supply included
Internal re-chargeable Lithium Ion batteries
Advanced power management – fast charge mode (30 days Easy Log capability between charges)
USB cable included
Storage bag included
4 sensor leads included
Optional Bluetooth
EasySense Q Advanced is our top of the range datalogger capable of fast logging, remote datalogging or general-purpose data capture beside the computer. The menu is intuitive for teachers and learners alike.
EasySense Q Advanced is also a stand-alone timer, able to record and review time, speed and acceleration measurements.
EasySense Q5 Logger

http://www.dataharvest.com/Products/easysense/q5.htm
Specifications:
4 X 20 Character LCD Display
USB Compatible communication V. 1.1
10 Bit Sampling
Max sampling rate of 50/second
Memory capacity of 4 data sets
Lithium-Ion batteries
Max Recording duration of 30 days
The EasySense Q5 comes equipped with five useful built-in sensors (light, temperature, sound, humidity and pressure). The values for each sensor are all displayed on the 4-line LCD screen and changing data values can be easily recorded with a couple of button presses.
The EasySense Q5 has two ports for connecting the full range of SmartQ sensors.
What can it do?
Measure data from all of its seven sensors simultaneously
Measure and display graphical data while connected to a computer
Measure and record up to 4 data sets while disconnected from a computer
Measure data from the full range of SmartQ sensors
Data Harvest Sensors:
http://data-harvest.co.uk/datalogging/sensors/smartq_s.html

http://www.fourier-sys.com/product_data_multilogpro.html
MultiLog is a hand-held data collection system for logging, monitoring, measuring and analyzing data with a keyboard and LCD display window. Easy-to-use software program performs highly sophisticated analysis (curve fitting, FFT, etc.) when the data is downloaded to a computer.
The MultiLog and EcoLog (sold in the US by Data Harvest International) are also used in the Fourier-System Weather Station. Station mobility enables users to investigate interesting phenomena of microclimates, near walls, in the city or in the garden. The Station is equipped with data radio transmission to the computer, avoiding wiring between the PC and the station. The station analysis software, Weather-Lab, is a graphic, friendly software describing the weather parameters via vivid icons, meters and graphs.
Specifications:
Up to 8 simultaneous analog inputs
Up to 2 simultaneous digital inputs
65 available external sensors
RS-232 PC host interface at 19,2000 bps
USB communication (optional)
2 digital control outputs
Capacity 104,000 samples
Resolution: 12 bit (4096 Levels)
Rate: variable from 1 Sample/Hour to 20,800 Samples/Sec
Full Keyboard: Enables manual programming
LCD graphic display: 64 x 128 pixels, shows logger setup and measured data
Stand alone operation: works and samples without computer connection
Automatic sensor recognition (for 4 inputs)
Programmable or manual trigger
Automatic calibration of sensor offsets
Built-in timer for delayed logging
Memory backup battery: data saved up to 5 years
Built-in clock and calendar
Built-in 7.2V rechargeable battery
Event recording
Voltage: internal 7.2V NiCA battery or external 9V to 12V DC input
Battery life (no sensor connected) 50 hours
Fourier-Systems Sensors:
http://www.fourier-sys.com/product_sensors.html
Teacher Support:
http://www.fourier-sys.com/teachers_teacher.html
PASCO Xplorer Datalogger PS-2000

http://store.pasco.com/pascostore/showdetl.cfm?&DID=9&Product_ID=51034&CATID=31&Detail=1
Specifications:
In the classroom the datalogger directly connects to the computer. Students collect real-time data and see it displayed instantly on their computer screens. In the field it collects data from under a second to an hour, a day, or a week. When your students are finished, they just plug the datalogger into the computer and download all the data, identified by time and type of sensor.
PASCO ScienceWorkshop 500

http://store.pasco.com/pascostore/showdetl.cfm?&DID=9&Product_ID=1443&Detail=1
Specifications:
Communication Speed 19.2 kbaud
Crystal-controlled timebase ±0.01% accuracy
Analog Inputs Three analog channels:
A: Differential Input -- 2 M Ohms impedance; gain = 1 or 10
B: Single Ended Input -- 200 k Ohms impedance; gain = 1 or 10
C: Single Ended Input -- 200 k Ohms impedance; gain = 1
±10 V range (±0.02 V + 0.1% of reading); 5 mV resolution
12-bit ADC converts samples
Digital Inputs Two digital I/O channels
5 µs timing resolution
Datalogging mode without a Computer Disconnect from your computer and take remote measurements.
Low power consumption mode prolongs battery life.
50 KB Storage Buffer: Collect 17,000 Analog (force, voltage, etc.) data points or 7,000 Motion Sensor data points.
50 KB data storage buffer (2N+1 bytes/sample period, N=# chs, eg: 2 chs @ 10Hz for 1,000 seconds)
Multiple data runs are appended to buffer.
Cross-platform Data Logged data will open on either a Macintosh or Windows-compatible computer. The interface stores the sensor and data display information so it knows what experiment setup to open.
Power Supply 9 V@500mA DC supply or a battery pack (4 AA). All inputs and the serial interface have ESD (electrostatic discharge) protection circuitry that works with power on or off.
Students can set up an experiment using the 500 Interface, disconnect from the computer to collect data at their lab table or outside the classroom, and then reconnect for data analysis.
PASCO ScienceWorkshop 750 with USB Interface

http://store.pasco.com/pascostore/showdetl.cfm?&DID=9&Product_ID=52587&Detail=1
Specifications:
Power: 12 VDC to 20 VDC at 2 A, 2.1 mm jack
Digital Channels: 4 identical channels, TTL compatible (8 mA max. drive current)
Maximum input logic transition time: 500 ns
Edge sensitive-sampled at 10 KHz. (1 µs res. for Motion Sensor
Analog Input Channels -- 3 identical channels with differential inputs and 1 MOhm impedance
±10 V maximum usable input voltage range (±12 V absolute input voltage range)
3 voltage gain settings on each analog channel: 1, 10, and 100
Small signal bandwidth up to the ADC: 1 MHz for a gain of 1, 800 KHz for a gain of 10, and 120 KHz for a gain of 100; input amplifier slew rate: 1.2 V/µs
Electrostatic Discharge (ESD) protected -- Both digital and analog inputs have ESD protection.
12-Bit Analog to Digital Conversion -- 5 inputs: channels A-C, analog output voltage and current.
Voltage resolution at ADC input: 4.88 mV (.488 mV at a gain of 10, 0.049 mV at a gain of 100)
Current measurement resolution: 244 µA, (1 V = 50mA) mA
Offset voltage accuracy < ±3 mV. (For measuring full-scale voltages the total error is less than ±15 mV, accounting for the gain error in the input amplifier.)
Sample rate range: once every 3,600 seconds (250 KHz) (Conversion time for consecutive channels in a burst is 2.9 µs.)
8X oversampling for better accuracy at sample rates less than or equal to 100 Hz.
Analog Output -- DC value ranges: -4.9976 V to +5.0000 V in steps of 2.44 mV
Accuracy at the DIN connector: (±3.6 mV ±0.1% full scale)
Peak-to peak amplitude adjustment ranges for AC waveform: 0 V to ±5 V in steps of 2.44 mV
AC waveform frequency ranges: 0.001 Hz-50 KHz, ±0.01%
Maximum amplified output at the banana jacks: about 300 mA at ±5 V, current limited at 300 mA ±12 mA
The ScienceWorkshop 750 Interface provides sensors and probes to study mechanics, waves and sound, optics, electronics, nuclear, and thermodynamics while connected to a computer.
Pasco Sensors:
http://www.pasco.com/products/cat/31.html
Teacher Support:
http://www2.pasco.com/training/

http://education.ti.com/educationportal/sites/US/productDetail/us_cbl_2.html
Specifications:
4 channels: 3 analog inputs, 1 combined ultrasonic/bi-directional digital port.
1 Mb Flash ROM memory(Operating System is electronically upgradable, update built-in user program, ~600K bytes available for archiving).
Multi-purpose user program for TI-73 Explorer™, TI-82, TI-83, TI-83 Plus, TI-86, TI-89, TI-92, TI-92 Plus built into the Flash memory(easily transferred to the calculator with a button push).
User programs will be language localized(available on TI Resource CD and TI Website).
50,000 sample per second data collection rate(maximum rate).
Collect up to 12,000 samples and store them on the RAM of the CBL2.
24K bytes RAM available on CBL2 for data collection.
Collect data with the push of two buttons using the Quick Setup feature of CBL2(without the use of a calculator).
Ability to store experiment files along with data sets in the Flash memory.
Can retrieve stored experiment files using any supported calculator.
Ability to use CBL2 Flash ROM to store(archive) any type of user programs or Applications.
Compatible with most existing CBL programs.
3 LED's on the CBL2 for direct user feedback.
One-handed design(unique docking cradle(included) with attach calculator to CBL2).
More than 40 sensors are directly supported with built-in calibration information (TI and Vernier sensors).
New stainless steel temperature sensor, voltage and light sensors included.
Ability to add custom sensor to the Sensor menu.
Ability to "power up" sensors requiring stabilization period(pH sensor, CO2 sensor).
Real-time data collection from multiple channels.
Real-time velocity measurements through sonic channel.
Compute 1st and 2nd derivatives on collected data.
Sophisticated data smoothing algorithms built-in.
Real-time data smoothing available on analog and sonic channels (light, medium, heavy).
Record absolute or relative time as data is collected.
Will be compatible with TI Interactive!™
Collect data on up to 4 channels simultaneously.
Battery voltage regulator for improved accuracy at low battery levels.
Port for connecting to supported calculators and TI-GRAPH LINK™
Computer based CBL2 Flash Manager Software available.
AC adapter port.
4 AA batteries included.
6 inch unit-to-unit link cable included.
CBL2 User Guide with classroom activities included.
TI Resource CD with Technical Reference included.
Let your students discover how math and science affect the world around them by developing hypotheses, conducting experiments, and forming conclusions. The CBL 2, the 2nd-generation Calculator-Based Laboratory™, provides the easiest, most accessible way for students to collect and analyze real-world data!

http://www.vernier.com/mbl/labpro.html
Specifications:
Windows or Macintosh computers, via USB or serial port, with our Logger Pro data-collection software.
TI graphing calculators: TI-73, TI-82, TI-83, TI-83 Plus, TI-83 Plus Silver Edition, TI-84 Plus, TI-84 Plus Silver Edition, TI-86, TI-89, TI-92, TI-92 Plus, Voyage 200.
Palm Powered™ handhelds: Palm T|X, Tungsten E2, T5, T3, C, W, T2, T, Zire 71, m515, m130, m125, m500, i705, and many legacy, Palm, and Visor handhelds.
Samples up to 50,000 readings per second
12-bit A/D conversion
Internal memory stores up to 12,000 data points
1 channel analog output, ± 3 volts, 100 mA (with function generator)
The Vernier LabPro is compatible with over 50 sensors. The Vernier LabPro is the only data-collection device that offers you four different ways to collect data. You can use LabPro with a computer, Texas Instruments graphing calculator, Palm Powered™ handheld*, or on its own as a remote data collector.
Vernier Go! Link

http://www.vernier.com/go/golink.html
Specifications:
Connect any one of 43 compatible Vernier sensors to your Windows® or Macintosh® computer with the Go! Link interface. Measure real-life phenomena such as light, force, sound, pressure, force and more! Just plug in the Go! Link into your computer, plug in a sensor, start the Logger Lite™ software, and click "Collect" and see the data collection in real time!
Vernier LabQuest

http://www.vernier.com/labquest/
Specifications:
320 x 240 pixel color touch screen
Rechargeable, high-capacity internal battery
40 MB built-in storage and SD/MMC card slot for expandability
Built-in temperature sensor and microphone
Vernier Sensors:
http://www.vernier.com/probes/
Teacher Support:
http://www.vernier.com/workshop/index.html