I love the keys for badges.
I'm not fond of the circles for answers, though. I prefer, as someone else mentioned, the idea of cylinders for answers.
Also, like many have mentioned, the logo is nice, but not unique. I hate criticizing it, though, since I don't have anything helpful to say on how to change it.
And when I do try to improve on the logo, I end up with this, which isn't any better. ;)
And when I do try to improve on the logo, I end up with this, which isn't any better. ;)
Other than that, I really like it.