Recently we discussed some of the problems plaguing mobile social networks. These problems include location, marketing strategies and compatibility issues. Our readers also contributed their thoughts on hardware compatibility and GPS. While no network is perfect, in this post we profile some of the key players in the market. Here's a look at four mobile social networks that may have what it takes.

We've already profile Brightkite as a winning mobile social network in the arena. Brightkite allows for your network of friends to keep track of where others may be at any moment. Since no GPS is required, users can send updates to the service via text messaging or email, to update their profile with location updates, pictures, and notes. With a host of privacy settings to prevent any form of stalking, Twitter users are increasingly using the network to update friends with status locations sent to their Twitter streams. Brightkite may be one of the best mobile networks to use, especially when going to a conference or big event in town.

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