I like the idea, but the site is fairly buggy:<p>* After signing in via Github, it asked me to create a username. I did so, but clicking either buttons on the dialog that displayed did nothing (incidentally, I probably shouldn't be able to resize that dialog).
* I clicked the "Sign in" link in the upper right and the dialog popped up again, again not working. I closed it, clicked the "Sign in with Github" button, and was taken to my profile page.
* In clicking around my "wall", I got it into a state where clicking the "All Activities" button does nothing. I have to click the logo in the upper left to get back to my "wall".<p>Like I said, though: neat idea.