http://www.linuxquestions.org/hcl/index.php/cat/200
Pick your favourite vendor and see if there are web cams from that vendor mentioned in the HCL camera section that are reported to work. Note that the drivers are for the kernel, and therefore don't basically depend on your distribution - you can always get them if you recompile the kernel, and in Ubuntu's case there is a high probability that the driver already is in the kernel, or is easily installed. If the reports say the device works with Ubuntu, it's even better.
HCL stands for Hardware Compatibility List - whenever you have doubts if a hardware piece works with Linux, check HCL first.
