Diptic is a fairly simple program that lets you make cool-looking collages using photos you take with your camera or what you have stored in your iPhone's photo library. You start by selecting from 20 different layouts, such as one photo across the top with three smaller ones across the bottom, or one big image on the left with four small shots down the right side, as examples. Then, just add images to each frame and move or zoom each one to make it fit just right. From there you can rotate an image 90 degrees within a frame or create a mirror image of the shot using the Transform features. Finally, you can adjust color, brightness, and contrast to bring out certain shots or make them similar to the others.
Diptic is a great idea for creating quick collages, but it seems like it needs a couple more things for it to be a great app. For one thing, you can't add text to your collages or individual images, which could be useful for calling out each picture. You're also limited by your sharing options with only the capability to e-mail your finished collage or saving it to your library. Something like Facebook (or other social site) connectivity would be better. But even with these minor issues, Diptic offers a fun and easy way to make neat looking collages quickly, and is a good option for people who want to do something more with their iPhone images.