You are ranked by other memebrs who then decide what rank you should receive. I believe it's based on the number of knowledgeable posts you make and the number of knowledgeable topics you partake in discussing in the chatter.
It doesn't have anything to do with posts, I've made quite a few posts and still no rank (not that I care why do I need a pretty bar to tell people what my bio already says) while I see people who have a rank and have made none. Also if other members rank these people I'm a member and I don't see a ranking button...?
Desi, you do have a rank, its Novice. Some people that do not have one are ranked as fluffies, or have not been voted on. I was told at one point that some of the members like to wait and see before ranking someone. Other times you get a rank out of nowhere by someone that feels you deserve it. I would not put too much stock into it. That "funny little bar" cant tell you what a person knows, or what they are like. I have met some beginners that knew way more then people with higher ranks.
That's very true madangel (however I didn't have a rank yesterday :)) but I guess it is somewhat useful if the people able to vote are all higher levels because you can say anything on your bio like that you've been studying for twenty years when really you've just started. So if it goes on forum postings along with the chat and how much you really know I don't see any problem in it.