The server part is used for persistent storage, so a user might have multiple computers open each with a Gears database but they all sync up to the same server

The server part is used for persistent storage, so a user might have multiple computers open each with a Gears database but they all sync up to the same server DB. Hopefully, once Gears is available for Mobile Safari, you'll be able to access your list on your phone both online and offline and sync back and forth. Plus it's also for people who aren't using Gears, like Safari/opera users.