I am trying to get my webcam to work in Linux, it shows up as the following with lsusb:

Bus 004 Device 004: ID 0c45:602c Microdia Clas Ohlson TWC-30XOP WebCam

I've tried every driver in the kernel (I believe the correct driver is spca5xx) and still xawtv yields:

This is xawtv-3.95, running on Linux/x86_64 (2.6.30-gentoo-r4)
WARNING: v4l-conf is compiled without DGA support.
can't open /dev/video0: No such file or directory
v4l-conf had some trouble, trying to continue anyway
v4l2: open /dev/video0: No such file or directory
v4l2: open /dev/video0: No such file or directory
v4l: open /dev/video0: No such file or directory
no video grabber device available

I don't know if this is related to DGA or not, but I know that the Nvidia drivers don't support DGA. I'm using Gentoo by the way. It seems that if I take the DGA flag out of make.conf and run 'emerge -N world' it doesn't seem to affect video4linux anyway. At one point the webcam did work, although it was extremely dark. I don't know how my setup has changed since then, but I know it's possible at least.

Any ideas?

you could try uvcvideo, quite a lot ofg new webcams have uvc drivers and so you may get success there