Currently Being ModeratedDec 4, 2012 9:23 PM (in response to heidi693)
You need Mountain Lion:
Purchase Mountain Lion in the App Store.
If your system does not meet the requirements for Mountain Lion you may be able to upgrade to Lion. Not all of iCloud's features are available with Lion.
To purchase Lion call the phone number in the Apple Online Store to purchase a download code. "Redeem" this code in the App Store and you will be able to download Lion.