Good discussion on rand(), people.
I just want to add that this is in General Programming and not For Beginners, so I think it's fine if people want to get into some more of the nitty-gritty details (well, it's not the Math forum, so maybe don't go overkill on the math 
). If, instead, this discussion is being intended for beginners, perhaps it should be in that forum instead... Just trying to encourage some good discussion.