Gist LLC has Slated Translation Keyboard (iTunes Link) for the iPhone, iPod Touch, iPad in the iTunes App Store for 99-cents (regularly $1.99) for a limited time.

Talk to friends in another language, even if neither of you can speak it! Slated translates while you type into your choice of over 80 languages! It can also translate what your friends send back to you in that language, instantly.

Slated is a keyboard extension – it can replace your keyboard in other apps, letting you converse in another language. As you type, it translates into your preferred language. Also, by simply copying any other text that’s in that language, you’ll see it translated back into yours. So you can and a friend can both type in a foreign language–even if it’s foreign to both of you!