Sonico, an Argentina-based social network raised $4.3 million from private investors and DN Capital, a venture capital first based in London.  Sonico launched around August 2007 and quickly rose to the ranks of the top 300 on Alexa.  Currently Sonico has about 17 million users registered in the social network.

One of Sonico’s unique features is a directory listing of its members is available at the bottom of the homepage:

Hi5, Orkut, Wamba, Vostu.com, MiGente.com, Quepasa.com, MyGrito.com, and Latino.MySpace.com are also pretty established in the same demographic.

Information Source:
[1] TechCrunch: Latin American Social Network Sonico Raises $4.3 Million by Mark Hendrickson