Given the recent failure of SunRocket, and Vonage's lack of profits and patent problems, you might find it odd to see VCs pouring money into yet another VoIP company.

On the contrary, investors recently handed over $10 million to Jaxtr, a startup that differentiates itself from the pack by letting users make and receive calls across its VoIP network using a mobile phone.

Jaxtr avoids long distance and international fees because it assigns the call recipient with a local number. Callers must use this number to reach the recipient, but Jaxtr taps into the social networking trend by encouraging users to post that number on their blog or social network profile, such as MySpace and Facebook.

The company has strong social networking roots. Its CEO is Konstantin Guericke, co-founder of LinkedIn. And its most recent investors--Draper Richards LP, Draper Fisher Jurvetson and Mangrove Capital Partners—also backed Skype.

Jaxtr is attracting customers by offering free service (100 minutes of long distance and overseas calls). As it grows its customer base, it will then look to advertisers for revenue. It also aims to deliver premium services.