The Panasonic PV GS120, GS200, & GS400 cams are tiny, tiny, tiny. Plus they are 3 CCD, while most handy cams are 1 CCD (3 CCD produces a more vibrant picture). I use a GS120 as a secondary camera, for a full stage shot or stationary "drummer cam" set up onstage. My main cam is a Sony VX2100, which produces picture quality nearly as good as broadcast TV. Between the two cameras, I've produced some nice 2 camera mixes.
The GS120 models can be purchased for about $500. The biggest drawback, I've found, is that the steadyshot function doesn't work in low-light environments, which most shows are. So you would need to have the camera on a stable surface if stealth recording (either on a ledge or in your lap). On the plus side, the built-in mic on the GS120 works quite well, even better than the built in mic on my Sony, which cost 5 times more.