Indeed, JungleDisk appears to offer a very similar service. I back up my entire main computer to JungleDisk (automatic incremental backup every midnight). On

Indeed, JungleDisk appears to offer a very similar service. I back up my entire main computer to JungleDisk (automatic incremental backup every midnight). On my minimal laptop for travel is a "Drive J:" which gives me access straight from Amazon's cloud for all the data on all the drives backed up from my main computer without local storage. One charge for the software, no extra cost for any number of virtually sync'd machines. Works great for a travel machine where you want access to all your data but don't want to carry it around with the risk of losing it; there's even a password to gain access to "Drive J:", so a lost computer contains no private data and also can't be used to access the cloud copy at Amazon.