I'm an American that travels somewhat regularly overseas (usually S. America and Europe) as well as a bit in the US. Generally when I rent a car I just add a navigation system. So far that has worked well, but I'm concerned if I ever end up in a spot where there isn't one available, and also that I am wasting money.

So I'm thinking of getting a navigation system, preferably a cheap and simple one that won't get me lost (the Hertz system I have rented a few times is perfect). I'm just worried that:
--I will end up in a place unable to get a signal (this could be unpleasant in a country where I don't speak the language, and in the US happens all the time with my phone navigation system)
--the maps are not up to date or useful

Does anyone have any tips so I can avoid those pitfalls? And also, any tips on how much I should spend are helpful--I really don't need any bells and whistles with this thing.

I had great results with TomTom downloaded to my iPhone. It can download map updates when you have data service, but otherwise it works completely offline - you just need the GPS signal and you're good to go.

I bit the bullet and bought a TomTom. My only complaint so far is that in Spain it shows a major highway in Andalucia that is still being constructed.

Thanks--I don't have an iPhone (or a smart phone that works in many places overseas), so I'm going to look into the TomTom.

Actually, after looking into it, I think my best option is to keep getting them through rental companies (and hope they have them).

I travel a bit around the world, and it seems adding maps is about $100 per continent. When all is said and done it would be a really expensive unit.

What do they charge per day ?

There was a TomTom that came with USA and Euro maps installed , the old model was a 930 , no idea what it is now

Soarer

The navigation signals are coming down from the sky, not off towers. What part of the world you are in makes no difference.

So long as you can see enough sky they'll work. What limited experience I have with trying to use a GPS in an area of tall buildings was that it usually failed, but it would work if I was in a more open area (say, a park.)

The signals come down on a very high frequency, they have little ability to penetrate things and thus you need a virtually unobstructed view to the various satellites.

IIRC you're only guaranteed that there will be 4 satellites at least 5 degrees above the horizon. Sometimes there will be more. The receiver must have fixes on 4 satellites in order to function, if it's built to handle more and it gets more the accuracy of the fix improves. (And note that last I knew there were no spare birds left in the constellation, if another bird breaks they won't be able to maintain worldwide coverage until a replacement is lofted.)

Note, also, that if you do get the requisite fixes in an area of tall buildings that means you have the birds in something like a line and that degrades the accuracy of the answer.

I have a Nokia 500 3G phone for this purpose. It costs just 119� without the contract, unlocked and everything.

Small, 3.2" screen, fast enough, can do GSM/3G (850/900/1800/1900/2100) and WiFi. Get a local prepaid SIM and you can have a Personal Hotspot, too.

The maps for 95 countries around the world are free (Nokia owns Navteq) and one can download them to the phone in advance.

I'm not 100% sure if route guidance still requires data connection for the route or if that is offline, too. I usually don't need navigation but just to know where exactly I am.

How good are the GPS chips in Phones ?

on my iPhone and Samsung Galaxy its very hard to get a fix , while the regular GPS sitting next to them has no problem .

I am sure the chipsets have improved over the years but what is the cut-off point where you do not want to get a phone or dedicated GPS older than that ?

Soarer

With or without data?

Most phones are good if you have a data connection available as they will use AGPS to get a fix. Once you've got the fix you can turn data off and they will keep it fairly well.

Without data, I've had shocking performance actually getting a lock on multiple phones.

No Data plan , just the iPhone and now illegal Galaxy Tab

Soarer

Using Scout from Telenav on iPhone. Just updated to have downloadable maps when cellular connection is lost. Great interface.

Jimbo

I haven't done extensive testing but it seems that A-GPS will work in several European countries without data roaming active. Worked in Spain in July on the iPad 3 (you can have data disabled but the device is connected to the 3G network) and also on a Nokia phone some time ago in Italy when the carrier's foreign data billing was broken and I hit the 50� limit in just a few hours -- the actual charge was less than an euro. The phone was complaining that there's no data connection but A-GPS got a quick fix.