I don't think they mean a lot. I got somewhere near 250 posts, actually, my last check was about 280. It's kind of nice for the other forums, but more often then not, you'll see me in forums that ANYONE can get into. Like redravin said, the avatar is just icing on the cake. For some people, such as myself, I had to have avatars turned off because for some odd reason, Jad's boobs might offend someone at work...
Just enjoy the community that has been created here, and you'll be surprised about some things.