[nevetS]

Talk more about what you're looking for with Bingo. That sounds like it might be an interesting project.

Like - for instance -
Do people get more than one bingo card? Or just one assigned to their profile? I could see something along the lines of a bingo card in the postbit that you could watch get closer and closer to winning.
Do they actively play? i.e. do they have to watch for numbers and mark them off their card? Or does the system automatically mark your card for you?
How do numbers get drawn? Automatically, with timing? Or perhaps based on user activity - like with every 5 posts, call out a number?

The hardest part of these things (from my perspective) is actually laying out the specification. Once that's done, it's a lot easier.