One vote for the Garmin iQue. It is another PDA with built in GPS (Same software as other garmin units) and I move it from my S to my Truck all the time.

the have a dash mount unit (no permanent attachment) that I find fits perfectly on the left hand corner of the windshield. It does not block my view at all, yet I can glance over to see my status.

I have hard wired a 12v outlet under the dash where the built in charger / speaker sits.

The only downside that I see compared to other units is a slightly smaller screen.

Also, as with ANY of these units, there is always the temptation to play around with it while driving. Ironic that the Nav unti would be the cause of the S leaving the road!

 

i have a navigation system on my pda for about 2years. it displays information on the screen and has voice. its all hand held and portable from car to bike. i can play mp3's in the background while i get voice navigation prompts. actually the system is:
bluetooth ClipOn gps receiver
ipaq5550 pda
software Mapopolopus for N America
custom molded ear buds.


THE GOOD:
over all it seems to work. there are several ways to enter in the start/ destination information, includes using your microsoft contacts list. the pda screen is some what day light readable but i most use the voice and i can run the microsoft media player at the same time. it sounds good, especially on the bike with the helmet on. i have a 1gig sd memory card in the pda and it holds alot of map information and has room for many mp3's as well. i have taken the unit on a long trip and it was useful. the map has business names listed. you can record your direction and speed into a file on the pda, the software displays it on a map. i have used this setup to look at the size of a acreage plot, determine how far i jog in the evening and i think it would work at the track with in its accuracy abilities. the pda does not have alot of audio output power so you have to use something efficient like a set of custom ear buds with the sound drivers molded into the plastic. they are moderate cost considering what some people pay for audio stuff, the ear buds also sound very good. as with any gps system you are free to go what ever way you want and the gps will re calculate the trip data, this seems to work.

THE BAD:
-i have nothing bad to report on the ClipOn bluetooth receiver itself. bluetooth is some what pretentious, say you separate the pda from the ClipOn gps receiver by more than 50 feet. the blutooth disconnects and will not automatically re connect.
-the mapopolus software behaves like a beta Microsoft application. i dont have time when i am on the road to baby sit its behavior. it does alot of things but not consistently. the pda has a microsoft operating system and nothing good can be said about it as well. you really have to be geek to put up with all this odd junk, some people are. there is a learning curve on this stuff not even considering its inconsistent operation.
-the mapopolus software has audio prompts. the people who wrote the software spend too much time in the office. for example; on a long run w/o any turns there are not any voce prompts that you are on the right track and or have so much time till the next turn. so if you are on the freeway, listening to the mp3 player, it may be hours before the gps system will chime in that everything is ok. the system in the mean time could lock up. the voice system is not all voice prompts and it has odd beeps at various events. it is hard to determine what beeps mean what. for example if you completed a turn ok it beeps on thing but if you elected to go another way the beep is another prompt, just hard to tell which is which. There are many software errors and it seems like they never QA’ed the stuff in some places and or management never considered how people other than them selves would use the thing.
-the gps software gets confused on a round about or sometimes if you make a u-turn but i think this is a common problem.
-you download the maps on a state by state basis but the packages are a series of files on a county by county basis. for a long trip this is a hassle. when you cross a state line you have to dork with the pda software to find the new map.

 

I'm on my second Garmin unit, it's a GPSMap 60cs

http://www.garmin.com/products/gpsmap60cs/

It'a a handheld unit as I use it for hiking in the mountains, but it works very well in my cars. Sometimes I'll just set it on the passenger seat or, when I'm a little more seriouos about it, I'll use a winshield or dash mount.

It'a got a color screen and has amazing battery life with just 2 AA's, though I'll usually plug it in when it's in the car. B uild in base maps are OK, but with 54meg or ram it'll handle a great deal of detailed maps available from Garmin.

On a recent trip from San Antonio (where I bought my '04 NFR) back to Chicago, I was able to load all the maps for the entire route and still had memory available.

It'a not a touch screen unit, and it doesn't talk to you, but there are numerous sounds that it can make to alert you that a required turn is coming up. When you get off course it recalculates your route fairly quickly.

Great little unit and for roughly $450 - $500, it VERY portable and accurate!

 

and now that i have gotten all this great advice it is leading me to believe that i should go mobile (portable) on the xm system too!
i am concluding that the electronic systems are changing so rapidly that it does not make sense to "build them in" to the car...
xm has some great portables that you can even carry outside the car (like portable gps)- when will they combine all this stuff!!! ?

so my next search will be for portable xm- i see a couple of choices and they are as confusing as the gps was before you guys helped out.

 

The Garmin c330 has a built in lithium battery that lasts up to 4 hours, so you can take it inside your house and map out your next destination. or walk with it down the street ( you can even but a handle bar mount for a bicycle.

You can sign up at garmin.com and they will send you emails to let you know when they have updated version of the maps that are pre loaded in the unit. Lots of people complain that their gps does not have thir house address on the map because their development is two or three years old, yet they never updated their maps. I've had my gps for 2 months and I have already gotten 3 updates.

 

the garmin 2610 is the way to go, you can move it from car to car. you also don't have to worry about charging the batteries. I built mine in with a panavise, but you don't have to, it's very portable. it's also has some nice features that the ones don't

as far as updating info, it comes with software, and you use your PC to do it. It's pretty easy to use.

 

alright guys...

after reviewing all of your info and checking out different units i concluded with the garmin 330.
i got it today and have been playing with it.
i like it cause it is small yet big enough to really work. i like the voice and the choices of views. and it is not the most expensive and not the least expensive. kinda in between with all the options that were important to me.
i can see that any of the suggestions above would also be good choices.
this thread is a great resource for anyone looking for a portable gps.
after owning one (although only one day!) i am certain that portable ones are the way to go- and i like the ability to download updates into it easily.
a feature that i find really neat is you can type in any location by name or by address- as you begin to type the unit already has ideas of what you are looking for and will give you choices- you then just pick the exact one that you want.
really neat !!