I forgot to mention in the original post, but this did have a time limit -- I was going to drop the reward once it cycled out of the topic in the #xkcd IRC room (which would happen in about 2-7 days). It's cycled out now so I'm going to post the original sentence and withdraw the reward.
The sentence was "When all else fails, a new person can always bring more guns."
The associated hash (for verification) was "c612c2961c582be831486251188f3e86e7d979d865f01ea5e3e9e910a5a7874fad4b5c3e067097d 0a6d7da2bd1c60a5fca0e1e925ea8c95b14bd757c53bb515d".
If you want, and just as a "for kicks" project, I can make another hash but I think I should probably put this topic to rest.
also in case I forgot to mention in the rest of the post, I'm officially withdrawing the 10 BTC bounty.