Logitech QuickCam Pro for Notebooks (USB) is the USB web-cam I use. I like the small size and the clip on mounting system works great with the IBM X31 Thinkpad.
Mandrake 10.1 includes PWC (Philips Web Cam, the chipset that is used) support out of the box, but it only supports QCIF images (176×144, quite small) images. To get support for full size images (up to 640×480) you will need to install the kernel source rpm, and visit this site to download the pwc-10 package. I had no problems installing it from the full source code (as opposed to just the kernel patches).

The Saillard code supports a compressed data transfer mode which allows you to get high-resolution images at a faster frame rate off of the CMOS sensor in the camera over the USB bus. Because the device is a USB 1.x device, it has limited bandwidth on the USB bus and must compress larger images (or faster frame rate data) to fit it inside of its bandwidth limit.