I haven't read through all the comments yet... I like the idea, the site's design is pretty awesome, but I'd suggest making the "Help a Hacker" and "Get Startup Help" buttons more prominent and easy to find. It actually took me a bit of hunting to finally find them on my profile page.

Might work well to have them on the index page _if_ you're signed in. Otherwise you get the copy on what the site is and how it works.

Just an idea :) Well done though!