30fps (technically 29.97) is movie frame rate so it will give a fluid feel to the recorded image (hand doesn't go from the tip to the base in a single frame causing confusion).

15fps is half frame speed and gets choppy but if you are doing webcast or teleconference it is better on bandwidth and communicates fairly smooth for a webcam...30 is better but eats up bandwidth.

In cam mics suck get an external one.

640x480 is pretty standard fare, any bigger and it has problems transmitting because of image resolution hogging bandwidth.

Still frame shots...get a point and shoot....even the cheapest digicam is better than 90% of webcams.