This is one of those apps that really exploits the large 9.7-inch screen of the iPad. It has a bunch of useful (and funny) messages and illustrations built in that act as backlit signs; just select a message, hold up the iPad and you can easily communicate with someone across a crowded or noisy room. You can even write your own message (with customised background colour and font) or connect it to your Twitter account to automatically tweet the message. Get it for free from the App Store.
