VantagePoint Venture partners has reportedly pulled its $20 million investment in mobile content firm 3Guppies Inc.-a rare move for a venture-capital firm-thereby apparently forcing 3Guppies to shut down its operations, RCR Wireless News reports.

You've probably never heard of 3Guppies. This author met with the firm last year, back when it was called Mixxer. It was yet another mobile social networking service that offered a wireless MySpace widget, before being rebranded as a ringtone and mobile social networking company.

That's one folding, with probably many more to follow, now that the first round of the social networking land grab on mobile appears to be cresting. Sometimes it's tough to see folks put a ton of effort into building their companies only to have them fail in the end. Such is the way of the tech industry.

3Guppies on the way out? [RCR Wireless News]