Flutter is the next big iPhone app. The app allows you to send unlimited picture messages and your geo-tagged location to most web-enabled mobile phones in the world. All you need is a wi-fi connection or existing data plan to have the convenience of sending multi-media messages (MMS) to virtually any web enabled mobile phone number in your iPhone contact book.
There's a small US$1.99 fee to download the app from the iTunes store. It's a small fee for a really cool application.