for Mac users running Lion, and for owners of any iOS device -- such as an iPhone or iPad -- running iOS 5 or later.

MobileMe, which cost users $99 per year, or $149 for a five-user Family Pack, has had a checkered history, during its 2008 launch, and was dogged by problems ranging from slow synchronization to extended email outages.

After MobileMe's launch debacle, Apple extended subscriptions by 30 days and turned the service over to a different executive. Then-CEO Steve Jobs also issued a to employees that said MobileMe was "not up to Apple standards" and that it had been a mistake to launch it alongside the debut of 2008's iPhone 3G and App Store.

Current MobileMe subscribers who switch to iCloud retain their email address, and their email, contacts, calendar and bookmarks are automatically migrated to the new service. Files stored on MobileMe's iDisk -- there's no comparable iCloud component -- must be before June 30.

According to the , which yesterday reported the free Snow Leopard offer, Apple has been emailing MobileMe customers notifying them of the deal. Others can request a copy of OS X 10.5 by steering to and signing in with the Apple ID linked to their MobileMe account.