Online storage provider Box.net has raised $6M in a Series B round of financing led by U.S. Venture Partners and involving Draper Fisher Jurvetson.

According to the release, Box.net currently has over 1.4 million registered users and will use the funding “to continue company expansion, including the development and marketing of new services and products.”

We recently covered the launch of OpenBox, a way for third-party web service developers to build functionality into Box.net. The company raised its $1.5M in Series A funding from Draper Fisher Jurvetson mid-2006 when it had only 500,000 members.