I've just launched swytch.net, a little social network I've been working on for a month or so. It's nowhere near ready for public consumption but the core ideas are there and I'd be interested to hear what others think. Here are some of the things that I think differentiate it from facebook and co:
1) multiple profiles: having one set of "friends" from all your different social circles limits you to sharing only what you're willing to share with the entire group. On swytch, a user can have a separate, distinct profile for each social circle.
2) robust privacy: each profile is either public or private. Content is either open to anyone or restricted to your followers. There is no third tier - you don't have to worry about friends of friends accessing your data. Social networks need stronger, simpler privacy - not more privacy controls.
3) private by default. I think the perception that users don't care about privacy is way off the mark. Users don't always know about privacy settings and their implications but that's not the same as not caring. On swytch, everything is private by default. On private profiles, nothing but the username is revealed to non-followers.
4) location: sites like foursquare and gowalla offer this but they're too gimmicky. I think they have to be because their entire service is based around location, they have little else to offer. However, location data combined with updates, photos events etc is very useful.
Please kick the tyres and tell me what you think. There is no landing page yet but you can sign up here (only a un & pw are required):
http://www.swytch.net/sign_up
Edit: Signup was easy, the username admin was available. Sweet.