This is going to be very cool. Steve Gibson was raving about it on this week's Security Now, because apparently it's a pretty damn secure (in comparison to Dropbox) way to sync files over the internet, between folders. You can do two-way syncs, read-only syncs, one time syncs. Very cool, and it's free.
Right now it's in alpha, but apparently even then it's still pretty stable. What I like is that they're working on getting it functional on NAS's too, including FreeNAS.
Wirelessly posted ()
This also stands to dramatically increase "legitimate" (I.e. noninfringing) BT traffic. That will serve to strengthen BT against takedown, as well as certain methods of p2p throttling.