The OV519 chip is used in some cheap webcams - for example, from DSE (product code XH5096) sold as "Internet Camera with Microphone".
This USB WebCam supports 640x480 resolution images at 15fps, and video at 25fps, according to the box.
The 2.6 series LinuxKernel (as of 2.6.7 at least) come with support for webcams that use the similar OV511 chip, but not these WebCams.
However, 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.
The camera's built-in microphone is detected by the kernel's USB ALSA drivers, but it doesn't actually seem to work - a new sound device is registered (/dev/dsp1) but reading from this device doesn't do anything.
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.
Best bet (for now) is to get a camera with better linux support.
No other page links to OV519WebCam yet.
