Content Serving Cluster
patio11: Honestly, I think you're likely to find that Amazon S3 is the best option.  It costs money, but assuming your business generates money (many businesses do) it will probably be more reliable and cost less expensive, expensive you-time than anything else.Otherwise: rsync is your friend.  Run it in daemon mode.  If you've just got a handful of machines I'd nominate one machine as the server to receive all uploads.  Everybody else just syncs their upload directory to that machine's.You may also want to consider offering bittorrent as an option, since this situation appears to be tailor-made for it.