Since I'm much more familiar with computer stuff, I used "increasing its resolution" from the sense of increasing the resolution of the final image (i.e. more pixels with 720p than 480p). I didn't mean to imply that one can get more information/detail than the original image has. I realize that interpolation is no more than a extrapolation of what the image might've looked like if it had been recorded at a higher resolution, but it's nothing more than a "guess".
I wonder if I'm just overly fixated on the video processing, like what Faroudja or DVDO offer. Those products get very good reviews (and cost a pretty penny), so I assume that there's some merit to them. I guess it's also b/c I'm stuck with game consoles that I love but only output to 480i/p, so I'm trying to find a way to "spiff up" the output. I may also be biased b/c I have one of the earlier 19" LCD monitor (back when they cost >$700), which does a pretty crappy job of scaling anything that's not its native resolution. So, I try to run everything at its native resolution to avoid to monitor's internal scaler. Perhaps I'm making the same assumptions about 720p projectors, so that's why I'm trying to scale everything up to 720p before it's sent to the projector ...
