Mobile Social Networks

ABI Research on Mobile Social Networks, September 2008:
Mobile Social Networking
Gold Rush, Goldmine, or Minefield?
The mobile social networking market is best described as emerging. With a very large number of startups and unformed business models shaped loosely around Internet-based equivalents, the mobile social networking industry has a long way to go before it [...]

Juniper Research have just come out (May 2008) with a great Mobile Web 2.0 whitepaper

I thought I would show you the part about challenges:
Table 3: Key Challenges for Mobile Web 2.0 Applications
Technology Fragmentation
Variations in device capability are an intrinsic characteristic of the mobile Web environment and there are thousands of different models [...]