umm... Idk what to say
quoted from site
When it comes to informational data, most automobiles tend to be pretty stingy on details. You really get just the basics - speed, fuel, odometer, and engine temperature. That's not a lot of info especially when you're a tech-hungry geek - we want to see more and fortunately the Car Chip Pro delivers.
No tools or automotive expertise required! Just plug Car Chip Pro into the OBDII port (easily found under the dashboard or steering wheel) and it reads and stores data from your car's on-board computers, continuously logging driving and engine performance. On-board diagnostics (OBD) data was once available only to professional mechanics. With Car Chip Pro, this same data is now in your hands.
Easy Plug-and-Go Installation
Locate your car's OBDII connector. It's found under the dash of cars, model-year 1996 or later, no more than three feet from the driver's seat.
Plug the data logger in. A gentle push is all it takes.
Start driving. The data logger will start collecting data as soon as you start driving.
Connect the Car Chip to your computer via USB and download the data.
Easy installation: plug in under the dash, drive your vehicle, then download the data to your PC
Up to 300 hours of trip details (newest data records over oldest)
Complete trip details including time/date, distance traveled, speed (1- or 5-second intervals)
Log up to 4 of 23 engine parameters
Provides individual graphs and summary reports
Records/shows extreme acceleration/braking
Allows user-set thresholds for audible alarms, speed, acceleration, and braking (post-drive reports/graphs show when, for how long, and number of times thresholds were exceeded)
Automatic accident log with last 20 seconds speed data before impact
Assign trips as business/commute/personal
Calculate gas mileage
View/Reset engine diagnostic trouble codes (check-engine light)
Test for preliminary emissions status
Software (included) lets you review/clear diagnostic codes, view summaries/detail reports, and copy data to spreadsheets for further analysis
Includes: Car Chip Pro data logger, Software CD, USB cable
Software works with: Windows 98SE, ME, NT4.0, NT2000, XP, Vista
Dimensions: 1.8" x 1" x 1.32" (46 x 26 x 34 mm)
Edit: apparently there is more then one on thinkgeek