Apparently if you share music with less than 30 people at a time it is considered a private performance and is completely legal. That's the idea behind Grouper, a free peer-to-peer file sharing service which, rather opening your file collection to the general public, opens it to a group of people (less than 30 of 'em) you specify. Here's the other catch, which you'd better let your invitees know in advance. You cannot download each others' music, you can only stream it. This may come as a disappointment to your friends and family, but it's completely necessary if Grouper wants to obey the law. And, given the RIAA's relentless witch-hunts (more on that in another post), I'm sure they are playing it very much by the book.
Given these constraints, Grouper is still a neat tool. Keep in mind that while music can only be streamed, everything else (photos, documents, video, etc.) is fair game for downloading. Plus there is instant messaging (group and individual) built in. This could actually become a great business tool for teams in far-flung locations.
Just pick a folder(s) on your hard drive to share, send out a bunch of invitations and you're off and running. People accept your invitation, create their own account, share their files and you've got yourself a regular file-sharing commune.
You can immediately see who's online, search each others' files, chat with each other, and send out group messages. While the interface looks very cool, some elements of it, like the playlist, still need some fine-tuning. Also, the wide beveling of every element is fashionable, but wasteful. I'm sure skins will become available that allow designers to better use the real estate.
Ultimately, Grouper is a great free tool that will allow you and your friends to share music and files and have a little fun. It's available at http://www.grouper.com and costs nothing but some hard drive space.
Now if I could just get my brother Pete to join. I swear he has 4,000 albums....