It's awesome that you've actually taken action on this as an idea rather than just talked about it. (Like me)
I posted a similar idea, amidst several other ideas here that I welcome any and everyone to steal/modify and use for themselves. (Though I won't refuse equity)
http://lesswrong.com/lw/e26/who_wants_to_start_an_important_...
Message me here or at www.Facebook.com/AltonSun since we probably have some mutual friends if you're interested. (Directed towards everyone since I already know Michael as an awesome hacker that consistently cleans up well at top hackathons in the Bay Area.)
Your idea is better than mine for a couple reasons: 1. It's hard to measure whether someone really fulfilled your wish 2. Lower barrier to entry and simpler with just emails, you can reasonably charge the poster some nominal fee rather than the upboaters to keep noise to signal ratio low