The <i>only</i> thing I would ever use this for would be legal files shared with friends - I'm not sure how often Amazon ripples their IP addresses, but I'm sure the RIAA/MPAA would have a field day with an IP address linked to a billing account in the US.
Ouch. What would that cost for the bandwidth?<p>I looked into using cloud instances for file sharing (legal files, of course) and decided it would cost too much for what it was worth to me.
This is cool, you could also use S3 to help you seed if you don't want to keep your computer on all the time. S3 allows you to use torrents by adding ?torrent to the end of your urls. The data transfer is treated the same as regular S3 data access.