Namely, the 2" by 3" screen that the iPhones have.

If you're going to try to convince me that the iPhone is going to take over every in-car GPS device (Garmin, Tom Tom, Magellen, whichever), first you're going to need to show me how to get directions off a 2"x3" telephone screen *without* crashing the car.

Some Garmin nuvi devices have something like a 7" diagonal screen. I think they have it because Garmin designed it *for cars* and determined that you need something bigger than a cell phone to safely get directions.

There's another thing to consider that this article didn't even mention... the iPhone isn't even making the *iPod* obsolete! Why would anyone contend that a tertiary feature of a cell phone is enough to disrupt the market for primary-GPS devices?? If anything, I could see the GPS-capable phones inciting more interest in car-ready devices like Garmin and Tom Tom's.

Excellent point about the screen size. People serious about using these in the car aren't going to settle for an iPhone. But, that said, people serious about using them in the car either already have a car with a built-in unit or will within the next few years. (Within 5-10 years GPS is going to be standard equipment on the majority of cars.) Rather than worrying about the iPhone, Garmin would be better served assuring they are the major manufacturer who supplies these to car companies.

And a factor that must have Garmin petrified about the market for portable units pertains to the question of how large a segment is really serious about using the devices, as opposed to just wanting the coolest new gadget. The iPhone threatens to steal the second group completely away.

While it's true that GPS will be available in most cars in a few years, I suspect it will still come as an expensive option, just like the upgraded sound system on cars today. Most of the time you can get aftermarket stereos that are better than even the best manufacturer option, at a fraction of the cost. OEM options are outrageously expensive. C'mon, $300 for a built-in digital compass? The same technology is available for $20 (without the "built-in" look, of course. You just get an ugly plastic cover to remind you and your passengers how cheap you are).

And don't forget about portable GPS for other uses besides automobiles. I suspect GPS will be available as an inexpensive add-on to many other devices, even possibly becoming cheap enough to where it can be embedded in many ordinary items, maybe as an anti-theft measure or just so that they can be easily located.

According to Garmin's website, they offer exactly ONE nuvi with a screen larger than 4.3" diagonal (their "StreetPilot" line has the 7" displays), and currently Amazon is showing that 3 of the top 5 bestselling GPS units have non-widescreen displays that are SMALLER (2.8"x2.1") than the iPhone's (3"x2").

Not having used an iPhone or Google Maps+GPS but having briefly used a Garmin nuvi 3.5" model, I think the iPhone's size will in no way be a deterrent to those looking to use its GPS features. I long for the product that can combine the smoothness of a Google Earth-type display with GPS/driving directions functionality, and I think the iPhone 3G has the best chance at realizing that dream.