WebCam

There's a hundred different cameras called Logitech Quickcam.
Plug it in and type lsusb
You should see a list of devices, and your unidentified camera should be there.
Let us know the two numbers after the word ID.
They define the type of camera it is much better than the brandname.
There may be multiple lines

If you don't have lsusb, try this:
cat /proc/bus/usb/devices | grep Vendor

NiallB

Do you also have a TV card?
xawtv may need to be started with a -c /dev/video1 if you do.
Otherwise, try changing the input on xawtv through the composite/TV menu.
What does it give as options?

Take a look for camorama as another option.

Good luck,
NiallB