Loomia, which tells users what web content is popular among their friends, has raised $5 million in a first round of funding.

The San Francisco-based startup launched in June 2005 (our coverage of its early features), but it only released its SeenThis? application in January of this year (our coverage). The application allows you to see what content interests your friends on Facebook and other social networks. Loomia managed to enlist some high-profile partner sites: The Wall Street Journal Online, NBC Universal and CNET.

Loomia’s investors include Asset Management Company, Teléfonica Capital and Peacock Equity, the joint venture between GE and NBC Universal.