Common Social Network Features - Sharing, Friends, Tagging etc. Any existing libraries around?

[eluser]Unknown[/eluser]
The title kind of says it all.

Anyone got any insight to add?. I've tried googling but come up with nothing concrete.

If there are no exisiting libraries I'll build them myself and post them here when I'm done.

[eluser]WanWizard[/eluser]
Maybe Elliot Haughin’s “socialize” is a solution (CI 2.0 only though).

[eluser]Phil Sturgeon[/eluser]
This is not really something we could share as a "library" as it would require way too much custom code to get working.

We don't know what user system you're using, what permissions, what templating system, etc, so we can't just throw these things around like CMS modules.