Hello friends I did some search on social networking and tagging scripts.
I know everyone is looking for this nowadays.
Here is the list of all the opensource scripts that are available.
SourceForge’s one of the best when you’re looking for such things….
http://www.barnraiser.org/
http://sourceforge.net/projects/akarru/
http://sourceforge.net/projects/isticker/
http://sourceforge.net/projects/melt/
http://sourceforge.net/projects/mycomunicy/
http://sourceforge.net/projects/opennetwork/
http://sourceforge.net/projects/oscommunity/ *
http://sourceforge.net/projects/snoss/
http://sourceforge.net/projects/sociable/
http://sourceforge.net/projects/osstag/ *
http://sourceforge.net/projects/openpne/
http://sourceforge.net/projects/pligg/
I hope you will like it. Enjoy.
And, if you have some more, please add it:)
Updated: Found a related link right here: Social Networking scripts