Is it possible to launch the \"Photos\" application from an iPhone app? Similar to launching mail?
[[UIApplication sharedApplication] openURL:url];
The Photos app doesn't appear to register any URL schemes that other apps can use. There's a pretty well-established pattern in other system apps (e.g. Safari) of “saving an image” resulting in that image being placed in the user's camera roll; I'd recommend just sticking with that expected behavior, and perhaps using an alert to direct the user to look there for your app's exported image.
This article looks like it might be useful? Getting images from the iPhone