Since 1996 all vehicles sold in the United States have been equipped with an OBD-II system, also known as On Board Diagnostics. The reasoning behind requiring the system has a lot to do with the EPA and emissions, but it just so happens to also be a great tool for tuning. You may have noticed the required connector hiding around the dash in the vicinity of the driver's seat. Over time, various companies have developed OBD scanners and data loggers, but there were two of particular interest to us at the 2007 SEMA Show (we're covering the other later).
Magden Technologies brought out their M.1 Performance Computer, a compact box capable of logging the user's choice of OBD channels. The data is saved spreadsheet style and can be transferred via a USB dongle and the box also has the ability to log from user added sensors. The most interesting feature though, is the computer's ability to output video display. Combined with Magden's own touch-screen it makes for a pretty impressive interactive light show.