You must be wondering if it's possible to use emoji in your email, IM or Twitter updates. Well, the answer is YES!
Unfortunately, Apple has not enabled this and we need to do it manually. These are steps for a jailbroken iPhone.
SSH into your iPhone and navigate to User/Library/Preferences/com.apple.Preferences.plist. Edit it using a PLIST Editor and create a new boolean string KeyboardEmojiEverywhere. Set the boolean to True.
Most people don't jailbreak their iPhone so a workaround has been discovered. This is a slightly different implementation but people who desperately want emoji can give it a go!