Here's another interesting case-study in exploiting a bad RNG. It's from 1999 and shows how the authors were able to exploit the weak RNG at planetpoker.com to predict the sequences output by their card-shuffling algorithm.

http://www.cigital.com/papers/download/developer_gambling.ph...

Note that this is a case of someone breaking a system that didn't even use a cryptographic random number generator.

Sometimes I feel like I have a decent understanding of cryptology. And then I read an article like this and realize that I know practically nothing.

"Anyone attempting to generate random numbers by deterministic means is, of course, living in a state of sin." - John von Neumann

Simply hook up your RND to the logic circuits of a Bambleweeny sub-meson brain, give it a fresh cup of really strong tea and plug it in!