You can use iPhone’s front camera for video chat, but if you want more, the camera app Doubleshot Photo may help you.
Doubleshot Photo is a unique camera app developed by Mirko Tomic, and designed to offer you an easy way to use the two cameras of iPhone at the same time. Most importantly, the camera app allows you to combine the two photos respectively captured by front facing and rear cameras as one photo. This means that you can put your self-portrait in any landscape, and the built-in 28 different layouts and border effects let you create wonderful photos. Apart from that, the universal camera app supports AirPrint and geo-tag, while the integration of Facebook, Twitter, Flickr, Tumblr, Posterous and Imageshack allows you to easily share your photos with friends and families.
Doubleshot Photo with a size of 4.4 MB is compatible with iPhone, iPod touch and iPad running iOS 3.0 or later. At present, the universal app is free for a limited time. If you’re interested, jump to App Store for more details.