If you've got an iPhone, iPad, or iPod touch running iOS 5 or higher or a Mac running OS X Mountain Lion, you can use iMessage to send free text, photo, and video messages to anyone else in the world as long as they're using an iMessage capable device as well. Read receipts allow your contact to see whether or not you've viewed a message yet. While some people may consider read receipts to be a bit stalker-ish, others may find them useful for work and business situations.
