What are the Famous Social Networking sites in the world

The following sites are famous social networking sites in the world.Many people are using these sites daily

Facebook

Orkut

Google Plus

Twitter

Linkedin

Jaiku

Myhayastan

Efactor

Livejournal

Stumbleupon

Bebo

Blinklist

Digg

Delicio.us

Friendfeed

Plurk

                                          and

Linksgutter          etc.,