Sweden based iPhoneographer "ThroughTheiPhoneLens" has produced an amazing set of surreal images produced entirely on the iphone. Click on the last image below to see the whole floating series in his Flickr stream.
There are a few different ways to simulate a floating object, using an iPhone. Here's one of them:
Step 1.The first image is a background shot.
Step 2. The second image depicts the, soon to be, floating object on some kind of platform.
Tip: Be sure to take the second shot in exactly the same spot. Using a tripod will help.
Step 3. Using Juxtaposer I open both images and place the top image perfectly on top of the background.
Step 4. Then I just erase the platform and let the base image shine through.
Step 5. To fix the shadow I save the image and open it in TouchRetouch and work with the clone stamp. As always with working with floating objects - the shadow and light must be close to perfect not to spoil the illusion. Sometimes it may be easier to find an object that can actually float.
Step 6. Finally, for no particular reason, I add some blur and a couple of textures using Big Lens and PhotoCopier.
The final result: