Apple really is everywhere: even on the final Atlantis space shuttle flight that launched Friday carrying four astronauts and 2 Zero-G iPhone 4 smartphones.

The iPhones, according to the Today's iPhone website, have been stripped of wireless communications and boast external batteries. They're also loaded with the SpaceLab for iOS app, which will enable the International Space Station crew to conduct experiments in areas such as navigation, sensor calibration and radiation impact. One thing the app will enable the crew to do is take a picture of earth with the iPhone and calculate their relative position in space.

The iPhones are expected to return to earth in the fall via a Russian vehicle. At that time data collected by the phones can be analyzed.

You can download the SpaceLab app yourself here, though it's modified for earth's gravity and includes some simulated effects.