There is a driver (licensed under the GPL) that you can download from http://alpha.dyndns.org/ov511/download.html#ov51x - the module will be called ov51x. It should work with 2.2, 2,4 and 2.6 kernels. This driver has stalled in this form but there is some development going on with it slightly modified and this is known as the ovcamchip Module currently.
Unfortunately, these cameras serve images up in JPEG format only, and this behaviour will require application-level support. No webcam software for Linux seems to handle this (yet - at least for V4L version 1). The source code for the driver (linked above) comes with a small program that can grab and save JPEG images from the camera. JohnMcPherson has a modified version of this program that will display captured video in an X window - grab the "showvideo" package from our software archive. It appears there are some issues with JPEG patents - see here and here