air/fuel gauge
 

Does any body use them. Are they usefull or should I buy a different one. I already have water, and oil press.

I recently purchased a digital gauge from Nordskog. My car's been at Moroso for the last 4 weeks, so I haven't had a chance to put it in or tune with it. If you only have room for one more gauge, I'd go for a good EGT guage instead of A/F. If you get an A/F, get one with some kind of display on it instead of the bouncy lights from autometer. Nordskog has a couple different styles.
Have a look:
http://www.nordskogperformance.com/airfuel.html

Just remember that an A/F guage isn't going to give you a perfect reading unless you're going to spend the money for wideband O2 sensors. It's still a good tuning tool though.