Oh bobblefrog - go for it! Learn to belly dance! I am totally addicted to it and have fallen head over heals in love with it. It is soooooo much fun! It's hard work too - especially at first when you're learning to make your muscles do things that make you go cross-eyed!
I wanted to learn for years and years, but I was afraid to try. I thought I was too fat, too old, and everyone would laugh at me because I looked silly. Then last year I turned 40 and something 'clicked' - I thought 'so what' if I'm fat. 'So what' if I'm older. And finally, 'so what' if someone thought I looked silly - I wanted to do this for *me*, not for them. Why was I letting some hypothetical stranger stop me from living my life the way I wanted to?
In the end, the fat didn't matter - my teacher is very plus positive, and belly dancing is one form of dance where the extra weight can look just fine. My age didn't matter - as long as I can move, I can do something. And nobody has said one negative thing to me. On the contrary - the teacher, the class, and the troupe have all been so encouraging, and so many other people have said they wished they could learn too.
So - check out your local community centres, dance studios and gyms. You should be able to find something in your area. If you can't afford the classes, there are loads of 'learn to belly dance' DVDs out there. I have to say that a class is 1000 times better than a DVD (the teacher can correct you, and you can ask questions), so if classes are in your budget, they're worth it.