Business Networking Sites

http://www.sitepoint.com/social-networking-sites-for-business/
http://www.businessblog360.com/2009/04/30/best-business-social-networking-websites-for-entrepreneurs/

Sr. no	Business Networking Sites	Page Rank
1	http://en.netlog.com	6
2	http://follr.com	3
3	http://www.apsense.com	4
4	http://www.ecademy.com	6
5	http://www.efactor.com	6
6	http://www.manta.com	6
7	http://www.myproskore.com	4
8	http://www.spoke.com	5
9	http://www.startupnation.com	5
10	http://www.storeboard.com	4
11	http://www.tagged.com	6
12	http://www.upspring.com	3
13	http://www.xmarks.com	6
14	http://www.ziggs.com	6
15	https://foursquare.com	9
16	https://www.xing.com	8