Here's my example of a "Works with Linux" USB Webcam - Creative VF-0500

One such example of a USB webcam that works with GNU/Linux is the Creative VF-0500

I tested this device on Ubuntu 8.10 GNU/Linux, - (2.6.27-11-generic)

lsusb | grep Creative output:
Bus 003 Device 002: ID 041e:4036 Creative Technology, Ltd Webcam Live!/Live! Pro

Here are the programs that worked for me:

Skype 2.0.0.72 - must use this command to make it work:
LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so skype
per http://ubuntuforums.org/archive/index.php/t-997807.html

Cheese 2.24.2 (simple webcam program)

ekiga 2.0.12 (VOIP client)

Camera Monitor 0.2 (Simple Program to Show if the Webcam is on)

gqcam 0.9.1 - I used this command to make it work:
LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so gqcam -v /dev/video0

camorama 0.19 - I used this command to make it work:
LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so camorama

Here's a site that offers a USB Webcam that "Works with Linux" (unverified by me):
http://www.keenzo.com/showproduct.asp?M=LOGITECH&ID=3278315&ref=GB

Also checkout the links below for more information on getting your USB Webcam up and running in Linux:
http://www.linux.com/base/ldp/howto/Webcam-HOWTO/framegrabbers.html
https://help.ubuntu.com/community/Webcam

And for the Logitech webcam users that are looking for some GNU/Linux love:
http://forums.logitech.com/logitech/board/message?board.id=quickcam_software&thread.id=52709
http://www.quickcamteam.net