Jaiku, Zingku, and good ol' dodgeball are all acquisitions google made for mobile social networking.

http://www.zingku.com/
http://www.jaiku.com/
http://www.dodgeball.com/

Anybody know where one can get an invite to the first one?
This is for Jaiku: http://jaikuinvites.com/need-an-invite-to-jaiku/

They still haven't migrated to Google Accounts yet. GrandCentral hasn't either. I'd imagine when it does the contacts list will be merged with gmail's and can by sync'd with android which would be SOOOO convenient.
Invites to that: http://invites.mashable.com/site/grandcentral