Yes, MobileMe from Apple. Can’t complain, the synchronization between three desktops, two laptops (one a Windows PC) and the iPhone has been flawless. I also use the online storage for precious file backup. I don’t buy any extra storage space. I have used it for collaboration and meeting stringent company file management restrictions for an airport job. I had 8 other users exchanging and updating files with it. I also use it to broadcast calendars and synch email. I love it, it’s worth the money. Oooh, it also locates my iPhone if I forget where I put it. Very cool.