Plenty of people have been saying that while MySpace might be on top right now, the future of the social networking sector is in niche-oriented sites. We've looked at a few of these here on Webware--like BakeSpace, which is for cooking enthusiasts. Here's another one that just launched: Wellsphere, which is for people who want to live a healthier lifestyle.
There are a lot of health-and-fitness sites out there, and I thought that Wellsphere was a nice blend of being very goal-oriented (the personal goal is an integral part of the user profile) without looking too much like a weight-loss site--a very easy trap for a fitness site to fall into. But what I liked most about Wellsphere is that it's very information-rich, making it more than just a social network for amassinga friends list of fellow Pilates enthusiasts. There is a nice focus on user-generated resources, as members are encouraged to write up their own "wellspheres," which are short articles containing tips, tutorials, advice, and other health- and fitness-related information. And there are also searchable directories of both local resources (gyms, yoga studios, nutritionists) and fellow Wellsphere members who are looking for workout buddies in their areas.
The site design and navigability, however, could use some work. But Wellsphere is still in an alpha-test phase, so that's something that could easily change.