OBD-II Serial and Digimoto

[Wykydtron]

I found a guy who is selling this kit, which is compatible with my Samsung i730 PDA. I'm just curious if anyone out there knows how to use OBD-II Diagnostics. He says that it can work with Toyota's and Nissans.

Would this be a useful tool to have? Does anybody know if this can work for OBDI?

http://img.photobucket.com/albums/v685/Realchaos1/OBDIIKIT.jpg