The buzz in the tech world is that the 800-pound gorilla of GPS-that would be Garmin International-is about to get decked by no less than Apple, with the cudgel being the new $200 iPhone. Check out this on Slate where the argument is addressed in full.The gist of it is this: The new iPhone will include new functions to include turn-by-turn navigation and will sell for less than Garmins base Nuvi navigator. But the iPhone has the phone, the MP3 player, the wireless access and so forth. Garmins Nuvi line encompasses a dizzying number of products-more than two dozen-and is a mainstay of the companys consumer business.The iPhone, so the argument goes, forced changes in the recording industry by offering affordable and legal downloading of music. And it panicked competing cellphone makers to develop easy-to-use icon-based touchscreen technology, hence the Blackberry 9500. Is it poised to do the same to the GPS industry? Garmin, no stranger to tech competition, is aware of this and has announced-what else?-the NuviPhone–which comes at the iPhone from the GPS segment just as Apple comes at GPS from the phone biz.Im not convinced that a navigation-capable iPhone is enough to knock off Garmin, however. The reason is that turn-by-turn street navigation has to work with effortless perfection and precision-nearly good enough is about the same as worthless. Garmin sells truckloads of Nuvis because theyre simple, reliable, easy to use and uncompromised in their basic task: getting you where you want to go, without a lot of extraneous gewgaws larding up the process.Some users like the voice commands and, with no speaker, will the iPhone be able to do that? Probably not. How about mounts, antennas and the other accessories required by the would-be GPS ground navigator? Will Apple figure that out or get too hung up on the preciousness of sleek looks and an inscrutable operating logic? I have my doubts.Garmin, on the other hand, is likely to be no more sure-footed in the phone market. The last time they tried this was in a loser of a product called the NavTalk Pilot. Nice idea. Nice execution, too. But the world just didnt need a navigating phone or a phoning navigator. It may not yet.But never mind all that, the bright side for consumers may be more competitive price pressure on Garmins products, especially the bottom to middle strata of the Nuvi line. Id love to have a $99 turn-by-turn color navigator to replace the aging Quest I carry around in my briefcase.What interests most about this is how-or even if-Apple will conceive of ground navigation in a fundamentally different and better way than Garmin already has. Different is the Apple ethos, while Garmin has a lock on practical.This rumination has caused me to consider another question: What if Apple got into the airplane business? What would the FlyMac look like? Ill wager that we already know that. Given the laws of aerodynamics and physics, it would be indistinguishable from a Cirrus, but with one significant exception: The avionics would be simple to use with no training required and other than a home key, everything would be driven by touch screens.Come to think of it, I dont know why we dont have that already.