I found this really cool trick on OSXDaily.com that I just have to share.
First, you need a Mac with OS X 10.8 (Mountain Lion) installed. You’ll also need an iOS device and iCloud enabled on both.
On your Mac, create a to-do list in Reminders. Double click the to-do list that you created and it will open in a new window, which you can put anywhere on your desktop. You can then close the main Reminders window. You can hide this list by hiding Reminders but since the list window is smaller and cleaner, it’s a bit out of the way.
Now go to your iPhone or iPad, open Reminders and make a change to the same list that is on your Mac’s desktop. As long as both Mac and iOS device are online, the list will automatically update.
It’s one of those cool things you can do to impress your friends.