JMich: 1024x768 or 1280x1024. Mostly teaching code and debugging, and also presentations. Having a viewing distance of over 5 meters also helps quite a bit.
But yes, I was working with that as a screen, instead of the 15" monitors that were available at that time, or 17" if you were one of the lucky ones.
The biggest complain I had was that I didn't have access to a wireless keyboard to be able to walk around while demonstrating.
Crosmando: You teach a programming language?
And what I meant was playing games and internet browsing, your use seems to be somewhat unorthodox from the average user.
Sorry for late reply, telephone troubles and had to do a bit of troubleshooting/repairs.
Helped teach during University, mostly programming techniques and examples in Fortran 77 (Ugh...). Though that meant access to the Amphiteater with the projector, so I did have the experience of playing Starcraft and Unreal Tournament on a huge ass screen. Really reallly fun. As for internet browsing, it also works quite well, assuming of course you sit at a proper distance, and not be 5 feet away from a 72" image.
As to the use being unorthodox, I just (ab)use whatever's at hand. Hell, I have even played JA2:UC using the projector at my place, was a lovely experience. So yes, a big screen is a good thing to have, assuming you have the space to use it. A 30" screen at 2 feet is just stupid, no matter what you use it for (unless it's art restoration. In that case it might be small).