Need a little social interactivity

I’m looking to add a little social interactivity spice to my blogs.
More specifically I would like registered users to be able to work up some cred or points by contributing to the local community. Like commenting, voting, polling and such.
Is there any kind of framework for this already out there that you know of?
Personal home pages and links to the big social networks would be nice to but thats secondary as of know I guess.
Are there any interesting, live & kicking social networking plugins being developed out there?

Regards,

–Gunnar