MobileMe Features in iCloud
If you are or were a MobileMe user you had access to some of the features in iCloud. These features are a me.com email address (if you are a Mac user then you can still use your mac.com addresses), contact syncing, bookmark syncing, calendar syncing, and Find My iPhone.
The email address is pretty straightforward. You can get a free me.com email address with 5 GB of storage (shared with other iCloud services) to use on your iPhone, computer, iPad, etc. It can be accessed from iCloud.com or set up as an email account on your phone.
Syncing is pretty basic too. Any entry into the above mentioned services will sync to iCloud and they are accessible on any other iDevice set up with iCloud and/or with your Mac. If you make a change on one device it will show up on the others. For example, if you add a contact on your iPhone that same contact will be sent to your iPad.
Find My iPhone is great for finding your lost or stolen iPhone (or tracking your child who has an iPhone). With this feature enabled you can go to the iCloud.com website and see where your phone is via GPS. You can send a message to it and trigger a sound so it gets noticed, and you can remotely wipe it if you think there is no chance of recovering it. You can also do all of this on an iPad, iPod Touch, or another iPhone through the free Find My iPhone app.