1) Visit Diaspora.com

2) Install dropbox-style client.

3) "Connect" with your friends by facebook, twitter, google, oauth, email, etc.

4) Diaspora.com then shows all your friends files. Click "Download" to sync any file you want into your Diaspora folder. Any files you put in the "Diaspora" folder are shared with your friends.

5) Growl notification when a transfer completes-- open it from your Diaspora folder or play the media in-browser with the embedded VLC browser plugin.

Key Issues

* The UI would be stupidly simple-- everything happens in the browser

* No central index. All indexes are transparently synced P2P when both users are online.

* It's viral - any files you download into Diaspora folder are automatically shared with others by default.

* Privacy options let you limit bandwidth, restrict your friend list, etc.

* Embedded Web Server -- Diaspora.com would still be available offline.

* Embedded VLC Player -- Click "Play" to play media in-browser.

There are lots of legitimate purposes for the software. It's a like a free dropbox-- but with no central index it seems impossible to stop. The most exciting thing is that lots of normal people are now running the auto-updating "Diaspora Personal Server" and they don't even know it-- because it just works.