Apple announces MobileMe: Sync your PC, Mac, and iPhone
In other words, you can synchronize your Mac, PC, and iPhone. The service works with Mac's Mail.app, iCal, and Address book. On Windows, the service syncs with Outlook. In addition to PIM data, you can use MobileMe to syncrhonize photos from your iPhone.
Apple's Phil Schiller demonstrated the new service at WWDC this morning, showing you email gets pushed to all devices in a matter of seconds. There are also web based versions of the applications that look like desktop apps, including a photo application that looks like iPhoto.
The service will replace .Mac, and current .Mac users will automatically be upgraded to MobileMe. For new customers, the service will cost $99 per year for 20GB of online storage. There's a 60 day free trial available as well. MobileMe isn't live yet, but will be available at Me.com soon.