I installed a Logitech 2 MP HD Webcam Pro 9000 with Built-in Microphone. This works very well on my Fedora system. Unfortunately, sound did not work with skype.
Use System > Preferences > Sound to open the Sound Preferences dialog. Click on the Input tab and choose your input source. If I disconnect the Logitech Pro 9000 while Fedora is running, my input device changes from "Webcam Pro 9000 Analog Mono" to "Internal Audio Analog Stereo".
I did not need to do this with Fedora 12, but, I learned about it from a friend running Windows. Open your skype options dialog and select the "Sound Devices" tab. Uncheck "Allow Skype to automatically adjust my mixer levels". With this enabled, there was no sound.