At D4, the first on-stage demo is from SharpCast, a company we've seen previously (at Demo). The current version of this service allows you to synchronize your digital photos among multiple computers, your online Sharpcast account, and your mobile devices
It looks like a fantastic utility for people who are sick of trying to remember where their photos are. With this utility, all your photos end up in one place. Actually, they end up in all places, which means you don't have to worry about photo file management anymore. Cameraphone users will find it especially useful: photos you snap on a Windows Mobile-equipped phone will automatically show up in your account.
This concept goes beyond just photos, though. The vision behind the company is this: Users shouldn't have to care where their data is. For files, emails, calendar items, music tracks, photos, and videos, no matter where a user first puts an item, it should be available on all their devices or over the Web. So Sharpcast is adding synchronization to Outlook, "SharpCast-enalbing it," so that any changes made on your contact list (in Outlook or on your phone or on the Sharpcast site) are automatically synchronized to all your other devices.
Still to come: more data types and files. The will be a free version as well as premium accounts for more storage and features.
This looks like an incredibly useful utility, and it is addressing one of the biggest problems users are having right now: Too many devices, and too much data spread over all of them.