Edit: Since there was no interest, I'm just going to close it.
Here's how this is going to work, you're going to post with the amount of BTC you're going to bet(min 0.05, max 0.5) as well as a number 1-100. AFTER you post, send your bet to the latest address. If you do it before I will still count it, but you run the risk of someone watching the address in blockexplorer and stealing your bet. DON'T BET AGAIN UNTIL I HAVE POSTED A NEW ADDRESS. If it's right, you'll get sent 99% of what's in the pool excluding a 0.001BTC fee.
How cheating is prevented:
number|salt will be hashed using SHA1, once someone wins the salt will be posted and you can check it against the original hash.
For example, the number is 84 and the salt is helloworld. When this ia hashed using SHA1 as 84|helloworld, you get c90c49ca069a08964461b8b848511a833632a6ef, the hash will be posted before anyone bets. When someone finally guesses 84 I will post helloworld, then you can plug that with the number into a sha1 hashing function and verify that I didn't arbitrarily select someone.
There is one flaw in the above method, I could just tell someone the number. I guess you'll just have to trust me, I used to run a automated number guessing game, so I guess that adds a little to my credibility.
IF NO ONE GUESSES THE NUMBER BY FEB 17, 12:00AM PST(GMT -008) the winnings will go to the last person who made a valid bet.