I even have the gas price thing on iGoogle as one of my apps...so even that is accomplished with the iPhone using edge. It is programable for any zip or city/state. iGoogle is very easy to navigate and is pre-programmed in just like other posters are using on their "vehicle" GPS.
So, no one has yet to convince me that GPS is an all fired number one overall requirement for the iPhone.

Edge, Google Maps still has it covered.
Um...they're two different things. Google maps is just an interactive map. It doesn't know where you are, or when your next turn is coming up. It's up to you to know that and watch for it. If you miss a turn, its up to you to determine where you've ended up, what town you're in, and how to get back onto your route.
With a GPS, the GPS figures all that out for you. And tells you when to turn, and with a nicer GPS, will tell you traffic, give exact road names, bluetooth with your phone as a handsfree, etc.
So here's an example:
-I am in a part of my state with which I am not familiar. I pull up trusty google maps on my iphone, input my starting location, and where I need to end up. I follow the maps along, but come to a point where there is a major detour. I now need to figure out where I am, and how I can get back on track. I stop at a gas station, figure out what town I have ended up in, what their address is, plug THAT into google maps and start all over. And as I am navigating I have to take my eyes off the wheel and control google maps to know the next step.
OR
-I am in a part of my state with which I am not familiar. I turn on the GPS. I punch in my ending location. The GPS gives me turn by turn directions as I go. I hit a major detour. The GPS detours on the fly, and gets me back on the road. Because the GPS talks, I don't have to take my eyes off the road at all, and can respond solely to the verbal cues. Both of my hands remain on the wheel, I am not lost, and I am not forced to research my location in order to get to my destination.
I have tried Google Maps many times, and the biggest weaknesses are the lack of on the fly updating (as you make a turn, you need to input that you want the next step), the inability to detour effectively (if it's not a well designed detour, and you're frantically trying to figure out how to get to where you need beyond the detour, Google Maps is NOT your friend), and the fact that you need to actively interact with it, a VERY unsafe plan while driving, especially in an unfamiliar area.
Google maps is great if you know basically where you are, and you've got a friend to navigate you. Otherwise, dropping the money on true GPS is the better choice, hands down.