an interesting, and revealing read:
http://www.mcnews.com/mcn/technical/200511gauges.pdf

i have the AccuTire and the RoadGear digital gauges. Both are consistent with each other and various other gauges I've tried. They've proved to be quite durable too.

who knew the cheap pencil gauges could be accurate!?

I had thought about getting this RoadGear model as it comes in a form fitting case, but thought the price wasn't worth it: