Looking for a OBD II software solution

[2sa]

With gas prices many people have bought a product called Scangage II and found success monitoring their MPG... http://www.scangauge.com/

I would like to have a product like this that I can use with my 700Wx and have found that there are a few options available...Here are a couple.....

http://www.qcontinuum.org/obdgauge/

Has anyone tried anything like this? The site has a freeware program but I will need to purchase a plug for the car that is either wired or bluetooth. Interested in a DIY or review of a successful solution.