a ton of work would have to go into that.. it would be super expensive.. what's your plan for developing this?

This is the migration of several technologies and it's going to happen. The question is when? My Q. to you is, what type of resources do you have at your disposal and are you familiar with any of these technologies you wish to merge?

the new iPhone 3G?

Hi Eximio:
I have a few answers here.

First: convergence is merging GPS Navigation devices (PNDs) and Cell Phones in the very near future.

-- Go out and try a new Blackberry's Google Maps (or as creeper points out the 3G iPhone when it comes out)
-- There will be many smartphones with 3GPS being released over the next year. There are already several in Europe. Many of the things you note will be available.
-- nVidia recently release an applications processor with their trademark 3D performance, which would enable some of the Google Earth type apps requiring accelerated OpenGL

Also check out http://www.dash.net/

I'm not meaning to crush any hopes of a super GPS device, but this market is going to significantly change in the next few years.

As a startup, the best thing to look at would be to offer back-end services for connected devices to enable the location-based services you discuss.

My two cents on your possibly rhetorical questions:
Why doesn't it have a 2-way data connection?
>> Because then it would be a cell phone, or On-Star and then you'd have to pay monthly.

Why can't I put a SIP VoIP client on it and make cheap phone calls?
>> Assuming you have 2-way data connection, this would probably be a given.

Why can't I see the world in 3-D?
>> Because most mobile processors simply don't have the ability to run true 3D apps on embedded operating systems. Look at a Nintendo DS, which is a relatively modern piece of mobile SW, the 3D graphics are terrible compared to your computer.

Why can't I look at the weather 2 hours ahead of me on my trip?
>> This one is not a bad idea. This assumes you know where you're going.

Why do I just see a flat world?
>> See above. Also, if this was Google Earth, Google earth has Gigabytes of images and searchable points of interest. With a relatively fast broadband connection this seems seamless.

Why can't I see that I have a 5 mile climb ahead or a 5 mile decline ahead where I can put the car in neutral and coast?
>> Again assumes that you know where you are going. Most maps and "turn-by-turn" directions have been traditionally 2D applications. 3D Applications might be a way to innovate in this space.

Why can't I go to a web site at home and see my typical migration around town, the country, the world?
>> Sounds like a decent idea. But how does it make money? There is always the old Buddhist saying, "wherever you go, there you are." Many people think it's bad enough people need GPS to find where they're going. Now you want it to tell you where you've been. (this is sarcasm, in case it doesn't translate well)

Why doesn't my device alert me of cheap gas nearby?
>> This would be a dynamic points of interest. However, this assumes all of the gas stations around or some great citizen is constantly logging these in real time in a publicly accessible way. Yahoo and Google give access to things like weather via an API

Why can't I enter my expense reports through the Nav device?
>> Then wouldn't it be a PDA?

Why doesn't my wife know where I am right now?
>> BlackBerrys can do this already. They can transfer the locations of users to each other.

Why can't I surf the net from my Nav device?
>> Redudant question

Why am I not just looking at Google Earth, with it's 3-D view, instead of this flat world?
>> Redundant question. However, I believe Google's Android Platform will aim to integrate this.

Why isn't there an open API to this device's software?
>> Many of the GPS devices are actually WinCE-based. However, they simply don't have an ability to add 3rd party SW. Also, many GPS devices have a lot of IP and patents covering the various pieces, so the device maker may not be able to give access to everything. Again, Google Android may be a good starting point.

Google licenses its map data from TeleAtlas and Navteq so there really is no avoiding that.

I agree with your opinion. But,if someone who very poor want to have it,what should you do?

Can't wait until it comes into existence, next year or two???

cool idea gl

cool idea gl

I think the problem is that current technology cannot support applications. To develop a new technology would cost alot.