Thanks for everyone's input we are working on a probably fair system so people who do not know the history of me or the community do not think we will try to scam them for 2 dollars in bitcoin even know we give hundreds away a month.
Just to make sure you don't call it "probably fair": it is called "provably fair". The reason is that it is not only probably a fair system, but the user can prove that the server is not cheating.
A good example is just-dice.com. I ported the JavaScript verifiers to Python (see
https://bitcointalksearch.org/topic/m.10190283 ), so that a user now can verify from the command line, too, that the server doesn't cheat.
Should be easy in PHP as well, because it has hash functions like SHA256. And of course, you can't use rand(), because it might allow users to predict the server random number. You should use a hardware random number generator.
.
