We’ve talked before about how the next wave of file-sharing may be within private networks of people’s real friends, rather than on public P2P networks like BitTorrent. The latest example is a technology called Opera Unite, which is part of the next-generation Opera web browser. It lets users designate a folder on their computer to share with friends, and generates a URL that can then be distributed so they can share files. Of course, it’s not just about music or other copyrighted content, but it’s likely to spook rights-owners nonetheless. Opera Unite also includes a cloudstreaming feature letting users listen to their digital music collections from any computer.