iOS 5’s new Reminders app isn’t as full featured as some other Mac task managers, but it does offer some clever touches. One of them is the ability to sync to-do lists and share them with other users via iCloud.
You won’t find shared to-do lists in the app itself; you’ll have to log in to your iCloud email account. (If you get redirected to the Find My iPhone screen when you log in, click on the cloud icon in the upper left of the Find My iPhone page to get back to the main iCloud menu.) Even on the main menu, there’s no Reminders option, here you need to click on the Calendar icon.
On the left side of the Calendar view, you’ll see a list of your iCloud-synced calendars, followed by any iCloud-synced Reminders lists. If you don’t see any Reminders lists in the left pane, that means you haven’t yet created any within the iOS app. To set one up, click on the gear icon at the upper right, choose New Reminder List, and type in a name for your new list.
Once you’ve decided which list you’d like to share, click on its Broadcast icon (it looks like a WiFi signal icon). In the new pop-up window, enter the email address of the person (or people) you want to share that list with. When you add people to a Reminders list, they will receive an email. If they click to join, the list and its entries will then appear for them, on their iCloud and iCal lists, and in the Reminders iOS app. You can choose whether list subscribers can merely view the list, or view and edit it (the default setting).
You can select which Reminders lists you’d like to share by clicking on the Broadcast icon next to each one (the icon that looks like a WiFi symbol)