I've been tweeting about this a lot. Have you ever had the need to take two photos (maybe even iPhone screenshots) and just turn them into one image? For instance currently if i want to do so i would take screenshot A and screenshot B and then break out photoshop and create a canvas that is double the width of the original photo. You could also do this with a couple images you took of an event or something where say you want to arrange them in a certain order of fashion without having to do any real photo editing.
It seems to me that this is an obvious app idea. Drag and drop your images around and they automatically would move into appropriate positioning. Then maybe you can pinch certain ones to have a staggered effect. If there isn't one id consider breaking out the gloves again and making it.
Is there already something like this? Even if its not for iPhone or iPad specifically.