Local/social search product Loladex launched this morning, currently built exclusively around a Facebook application. The application will specifically seek to tap into the trust inherent in a group of Facebook contacts, as a source of information on, and interaction around, local business information.

Social media is quickly becoming the new local word of mouth. Yelp is testament to this, and Facebook’s Pages and Ads products are also steps in this direction. Few companies have specifically built Facebook apps to tap this potential, but we expect to see more.

For this to be useful to the average Facebook user, there will have to be a critical mass of participants (network effect) who add it to their Facebook account and actively participate in local recommendations. Review generation on social/local sites like Yelp face a similar challenge.

One of the benefits of Loladex’s strategy is that it taps into existing Facebook contacts and doesn’t require building a new profile or network of friends. This is one of the impediments to the social networking world continuing to grow: The average online user only has a certain amount of mind share for numerous social networking accounts and logins (Yelp, Facebook, MySpace, Twitter, Digg, etc.). At some point, a certain social networking fatigue sets in.

Loladex seems to sidestep this issue by building on Facebook’s popularity. The company will focus initial promotional efforts on the D.C. metro market, but it expects to quickly roll out other platforms and geographies, as it learns in that test bed. More to come later from Peter Krasilovsky, who had the chance to talk with founder Laurence Hooper about the “road map.”