updated 11:56 pm EDT, Mon October 15, 2012
Ability unavailable to iOS 6 users so far
Though the iOS-inspired Reminders app was a significant new feature of Mountain Lion, one of its abilities has been overlooked by most users -- a feature that lets users share reminders with other users. Until today, the feature was exclusive to Mountain Lion, and curiously absent in iOS 6. Apple has now added the shared reminders ability to the online iCloud.com version of Reminders, foreshadowing its likely addition to iOS 6 in a forthcoming update. Sharing a reminder makes it appear in the other users' Reminder app, or is sent to their email.
The change makes the feature available to those who are not using a Mac at a time when they need to share a reminder (such as at work), or need to do so from a Mac not running Mountain Lion. When making a reminder, a "Wi-Fi" image appears by the name of the reminder category, and when pressed prompts the user to share the email address of another user to which the reminder should be sent.
Apple will likely add the feature to the iOS version of Reminders in a future update, though there has been no official word on when that might happen. Trying to access iCloud.com on an iOS device redirects users to services such as Find My iPhone and Find My Friends or offers to help set up iCloud on the device, since most of the services on iCloud.com are already built into an iOS device.