Webcam Logitech Quickcam Messenger
The USB ID of this webcam is 046d:08f0 (lsusb command available in usbutils package).
You can have the camera working using the qc-usb-messenger driver, available as a package for gentoo, or at http://home.mag.cx/messenger.
To have the built-in mic working, you have to enable the kernel module snd-usb-audio, which you can find in Device Drivers / Sound / Advanced Linux Sound Architecture / USB devices / USB Audio/MIDI driver.