"Great!" You say. "But how much is this all going to cost me?" As Steve Jobs mentioned during the WWDC keynote, any user will be able to sign up for their own little piece of the iCloud for . They'll get 5GB and a free Me.com email address with which to store backups, documents, and mail archives. You'll also be able to purchase 10, 20, and 50GB of for $20, $40, and $100 a year, respectively. Any purchased content from iTunes (music, apps, and books) as well as your Photo Stream photos won't count toward this storage limit; they're stashed separately.

Like iCloud's predecessor, MobileMe, your mail, calendar, and contact accounts will be accessible from all your devices and on the Web (at ). You'll also be able to access your iWork documents, if you have one of the iWork apps on your iOS device.

As mentioned above, with iCloud you'll be able to wirelessly sync your contacts, calendars, and mail with all your devices. You can also sync reminders (from iOS 5's new Reminders app), Safari and iBooks bookmarks, and any notes you've made in the Notes app. In addition, your iOS devices will be able to sync any app data and documents and back up all vital information online.

Document & Data sync allows you to wirelessly work on the same project from multiple devices. Say you started a Keynote project on your iPad; you could add a few slides, save that project, and then open it up on your iPhone to do some last-minute tweaking--no file sharing or emailing copies to yourself necessary. Currently, the only apps that work with Document & Data sync are Pages, Keynote, and Numbers (Apple's iWork suite); however, the company has released an API for any third-party developers who want to implement this in their own apps, so we'll hopefully see more compatibility in the future.