I'm slowly getting addicted to Reddit. I just started browsing it a few weeks back and now it's gradually becoming my go-to place for a quick chuckle (/r/images is my favorite) or getting a glance at the current happenings (front page does this for me).
IMA section seems really interesting. That's place where folks start a new thread about 'Who' they are and offer to answer questions. Folks ranging from astronauts to prostitutes; mainstream celebrities to porn film stars have posted there and answered questions from fellow redditors.
Just a few minutes back I was reading about this guy who lived in the apartment building that was recently destroyed by the F18 jet crash. He and his neighbors who were in the apartment at the time of crash had helped save the pilot.
The average age of the folks there seem to be around 18-20 though. Although it tends to make the place trendy and current, it also makes it immature'ish at times.
They must have some comprehensive algorithm to determine which posts bubble up to the top within the sub-reddit and eventually up to their main-page. It probably has a lot to do with the "Up Votes" or "Down Votes" that one can give a post or a comment within a post.
Some links for n00b redditors (like me) to check out...
Reddit main page - Hot topics from all sub-reddits bubble up here
Images sub-reddit - place where I go to for a quick laugh
"I Am A" sub-reddit - Pretty unique folks post about themselves here
IAmA about the guy who saved the pilot in the crash mentioned above