Apple will be offering the Mobile Me service for $99 a year allowing you to get push mail, push contacts, push calendar, and more synced to your devices and maintained in the cloud.
MobileMe makes sure, that your iPhone, iPod touch, Mac, and PC is always current and always in sync. And with a suite of elegant new web applications, you can access your data from anywhere.
MobileMe stores all your email, contacts, and calendars on a secure online server — or “cloud” — and pushes them down to your iPhone, iPod touch, Mac, and PC. When you make a change on one device, the cloud updates the others. Push happens automatically, instantly, and continuously. You don’t have to wait for it or remember to do anything — such as docking your iPhone and syncing manually — to stay up to date.