I'll second dropbox. It's an excellent service and has saved my hide a couple of times. It's the biggest and best of the services out there as far as I know. Apple apparently tried to buy it, but the guy running it said to Steve Jobs that he always dreamed of owning his own business so he wasn't going to sell. Steve walked away without a purchase. It also underpins lots of iPad/iPhone apps for their filesharing/storage functionality. I'd expect that means they won't have any dodgy licensing/privacy bt I haven't read the EULA carefully so I can't say.