Zumba is a HUGE growing exercise craze. I started taking classes at my local Y about a year ago and got completely hooked. In fact, tomorrow I'm going to a training session to become a certified zumba instructor. If someone had told me 2 years ago that I'd want to teach a fitness class, I would have laughed them out of the room!
You can find classes in your area by going to www.zumba.com
Also, you can search for "zumba" on you tube to see some classes in action - lots of fun!