I'm guessing this is a product idea for Facebook / Myspace because otherwise I'm not sure what the marriage to them is. Personally I use Ventrilo when I want to chat. Skype works well and is free up to a point. It's hard to put up with anything after you use the big guns and vent just runs in the background so you log in, hop in a channel and that's it. If something like that would work I can give more details. If it just has to be within facebook I don't have a clue.

There are a ton of dice apps out there or you could even write one yourself for that matter. Random generators are pretty easy to code although I have never done anything in flash myself.