For about 3 solid months I've been using the Logitech Quickcam Pro 9000 Webcam.  It has a great 2MP resolution and can clip to the top of your laptop screen or rest on your monitor depending on your setup. It connects to your computer via a USB port. It also has a good quality built-in microphone so you can make sure you’re clearly heard. Dan Dooley used one for his town hall meetings in September 08. 

It costs about $99 but I've been seeing it advertised with a $40 rebate.

Like most webcams, it is used for situations where the subject is 2-8 feet from the lens.

There is a Mac version called the QuickCam® Vision Pro.