Our current favourite webcam is the Microsoft Lifecam HD5000, since it is autofocus, good resolution, relatively cheap, and a fairly small device.
Here's that HD5000 webcam with a 1/4" hole (using a drill press) and bolted to an Ikea Tertial lamp.
|We could have used a shorter bolt, but that's just what was here.|
We also mounted bolted on a piece of a soup can and used elastic bands to shock mount a $20 Rock Band microphone along with a pop filter.
And here's a Rocketfish webcam attached to an Ikea Sunnan lamp using self-stick velcro from a fabric store or department.