If you want to use a small laptop, I guess one option would also be one of those tv tuner pcmcia cards and monitoring the composite video out of the camera.

Just wanted to add my experience with the Ikan V5600 (5.6"), the little guy seems pretty ideal. It weighs a bit over a pound with a small sony L-series battery attached (got a bunch of cheap ones off ebay). It's really not much bigger than the on-camera screen but it's just big enough to get focus, and it has a higher resolution than other 7 or 8 inch monitors. The image quality isn't amazing and it stretches the frame when recording, which is weird but it still allows for critical focus during recording and decent playback for situations where you don't have (or can't afford) a larger field monitor.

-Nandan
Land of the Lost