For someone with a serious medical condition, this iPhone application could potentially save your life.
There's nothing complicated about Close Call, it simply lets you put a telephone number along with a message on your iPhone's wallpaper. It's how you use this information that makes all the difference. For someone with a serious allergy, it can be used to alert medical personnel of such, or if the phone is lost, a secondary phone number can be used in the hopes of a kind soul returning it.
The message can be put on any image in your photo library and once saved it it will then appear as your wallpaper. A handy tool in one sense but more importantly an essential one for those with certain medical conditions so for that I give it top marks.