iCloud Preferences on Your MacBook
Lion’s new iCloud Preference pane allows you to specify which types of data will be automatically pushed to your MacBook and iOS devices. If you haven’t created an iCloud account yet — or if you signed out of an existing account earlier — System Preferences will prompt you to enter your Apple ID and password. Click Sign In to display the contents of the iCloud pane.
The check boxes for each category are
Mail & Notes: Synchronizes your Mail messages and Notes between devices.
Calendars: Pushes your iCal calendars to your iOS devices.
Bookmarks: Synchronizes your Safari bookmarks.
Photo Stream: Pushes the latest photos and video clips you’ve added in iPhoto to other devices, and updates your iPhoto library with photos and video clips pushed from your iOS devices.
Documents & Data: Enable this check box to automatically synchronize the documents you create and your personal settings between your MacBook and other iOS devices.
Back to My Mac: Controls file and screen sharing across all the Macs sharing this iCloud account. Back to My Mac must be enabled on all computers that will use this feature.
Find My Mac: Enable this check box and you can locate your MacBook from a Web browser or your iOS device; also, you can choose to remotely lock your laptop — or even wipe your MacBook’s hard drive completely to prevent someone from stealing your data!
Locking or wiping your MacBook remotely will prevent it from being located in the future. These are dire steps indeed!
To display the storage currently being used by your Mail, Backups, and Documents, click the Manage button at the lower-right corner of the pane. Apple provides each iCloud account 5GB of space for free, but you can also elect to buy additional storage from this sheet.