I used Live Mesh once. Then, out of the blue, after a reboot reboot it started deleting all my files. I got in touch with the Live Mesh team and was told that I should remove files with unsupported extensions (WTF?) from my synced folders and see if my files came back. I think they were eventually able to recover some, but not all, of the stuff that was lost. This was early 2009, so maybe the client has improved since then, but I can't bring myself to trust it.