Also people want to keep their bitcoins hoping to get $100/bitcoin sometime in the future without gambling.
i've never understood this argument. if i plan to spend, i don't care if i spend bitcoins or dollars as i can fairly easily replenish my bitcoin stash.
here's what convinced me even more. let's say you generally have your savings in bitcoins. and then say you want to make a bigger purchase than the amount you have in your cash wallet but will be making the purchase either way.
which payment method will you prefer to use then? exchange bitcoins to cash, or will you prefer that they accept bitcoins and you just pay with those?
as far as the thread topic though, bitlotto (monthly) or bitlotto jr (weekly) are pretty good. 99% payout. all ticket purchases appear in the block chain so there is no question as to how many tickets were purchased and what the payout should be:
http://www.bitlotto.com http://www.bitlotto.com/jr.php