Open Source Social Networking

Open source social networking

Elgg

StatusNet

Dzoic Social Networking Software (paid)

PHPIzabi

Dolphin

Joomla! 1.5 with JomSocial, JomComments, myBlog or similar are hard to beat if you're looking for a facebook-like appeal, in my .02. but, I'm a tad bias ;)

Get Lat Lon - find the latitude and longitude of a point on a map

http://www.getlatlon.com/