Five mobile social networks you need to follow

Social networking is now synonymous with the wireless user experience--no other service better leverages the platform's signature combination of mobility, connectivity and location-specific accessibility. Research firm comScore reports that in April 2010, 69.6 million U.S. mobile subscribers accessed an application on their phone, an increase of 28 percent from the previous year--no app segment experienced more substantial growth during the period than mobile social networking, which grew 240 percent year-over-year to 14.5 million users. ComScore adds that social networking also ranked as the fastest-growing category accessed via the mobile browser, surging 90 percent over the previous year to close in on 30 million users.

The increase in mobile social networking users correlates with an expanding legion of social media services--competition is especially fierce in the geo-social segment, where startups including Foursquare, Gowalla, Loopt, Brightkite and Booyah are all vying for supremacy. Expect even more services to follow, from established players and upstarts alike. Here are five mobile social networks to watch in the months ahead.