I experienced Android envy for the first time last week when Google released their Sky Map for Android — envy, because in addition to using GPS and pitch & roll detection, the app also puts Android’s built in magnetometer to work, and that is not something my iPhone has.

Rumor has it, however, that the next iPhone will come with a magnetometer, and so we can assume that by this time next year, all smartphones will avail themselves of the GPS/pitch & roll detection/compass technology trio. What other uses could this technology be put to, besides pointing you to objects in the sky?

Probably the biggest potential is for photographs. If the phone can tell at what angle your are holding it and in what direction you are pointing it when taking a photo, in addition to where exactly and when (and what the viewing angle of the lens is), and you upload all this metadata along with the photo to the cloud, then services like Panoramio and PhotoSynth will have all the information they need to start constructing a crowdsourced 3D simulacrum of the world, photo by photo. PhotoSynth already does some of this by trying to calculate roll, pitch, direction and viewfinder angle of a photo by comparing it to photos taken in the vicinity, but it should get a lot better if it has starting values for these variables, even if they are not completely accurate.

I wonder how long it will take for DSLRs to incorporate this technology. There have been GPS modules for cameras for a while now, but (to me at least) the advantage of having coordinate metadata attached immediately to the image file by the camera is outweighed by the requirement of having the GPS unit be physically attached to the camera — Especially as a proper GPS unit can be kept in your rucksack, whose info you can use when downloading the photos to your computer.

Cheap pitch, roll and direction detection changes the game, however. Perhaps at first we’ll be taping our Androids and iPhones to the back of our DSLRs, but it can’t be long before camera manufacturers realize the benefits of having this information recorded by default. Then, when we upload our photos to the web, we’ll be able to automatically generate KML that lets us view the photos from the exact same vantage point in Google Earth.

Another use that this new technology will be put to is augmented reality applications. Sky Map is already an excellent example of a genre that should explode; perhaps we’ll see apps for superimposing names of distant mountain peaks on your screen (à la HeyWhatsThat); or an app that lets us “x-ray” the planet, so we finally know where precisely Buenos Aires is beneath our feet. Games will no doubt take advantage: Any empty parking lot could become a virtual maze, with the phone as your HUD — and you racing against your friends (both close by, in the same space as you, or on the other side of the planet).

In sum, there are plenty of reasons to hanker after tomorrow’s gadgets, considering the possibilities…