Calling all car geeks

[Farabomb]

I have been looking into OBDII adapters and apps for the charge and am wondering what is the best one out there. I have a few Suabrus and I would love a realtime diagnostic OBDII dongle and app to keep track of things. I need it to work on a 00 RS and a swapped 96 L with a 08 WRX motor. The swapped car isn't much of an issue as it's a track car but I would like to data log it when it's out on the road course.

Thinkgeek has one but I see cheaper ones out there. Just looking for real world experience before I spend the money.