I use a Logitech webcam (midrange price). I have a 15ft USB connection, and it works super. I am told images degrade if the USB extension is too long, but I have used the 15ft and a 10ft extension together, with no image degrading. I run two cameras off one laptop, and it works great. Funny, my more powerful laptop doesn't run one as well as my old laptop runs two... go figure
Dian
p.s... I like to mount my webcams on tripods. Once fixed on the tripod, I can just adjust the tripods without having to tape a webcam somewhere and have it sit stationery.