I've been using Bittorrent's Sync app for about a week now and I am quite impressed by it. For a long time now I've been looking for a simple and easy tool to get my mom's files replicated and this is by far the best I've found. Everything else required special configuration, port mapping, or firewall changes. But this is as plug and play as one could get.

I just wish there was a working open source alternative.

http://www.bittorrent.com/sync
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