>There's a few ways to do it, but what's usually done is to have a large bitmap filled with random values that's accessed by a function of threadID and current pixel (or whatever other info you have handy).

Do you have any good links that elaborate on this kind of technique? I had an idea that sounds a lot like this once, but being fairly ignorant about the topic I had no idea what to call it or how to implement it.

Thanks.