The revolutionary iPhone has launched a whole new business: the writing of small applications (apps) that run on the iPhone. From the $999 I Am Rich app (which was eventually pulled from the store) to the iPhone Zit Picker, everybody that has an iPhone has sprung for at least one app to customize their full featured phone. There are 15,000 apps available in the store and Apple is banking some serious coin by just allowing developers room to be creative. Hard to believe, but the 500 millionth iPhone App download has now been made!