While the forum thread "pledge" system works okay for development bounties, locating pledgors after the project is complete is dicey and often not enough to incent developers. The set up at fundable.org seems to solve this problem. Payments are deposited up front and a deadline/goal is set. If the goal is reached, payment is made. If the deadline/goal is not met, and here is the important part, funds are refunded to donors. I have no affiliation with these folks, it just seems like a good system and perhaps would be useful to incent Shadowmite and others since they can be certain they'll get paid if successful while donors get their money back if the project is not successful.