Travel Technology - Where exactly am I lost without 900 MHz for GSM?

Ok, tried to check a few of the sites I turned up here by searching and now my head is spinning. So just let me ask;

I use Cingular in the US and tend to buy sims overseas. Work takes me to Japan/Korea (I know the issue there), China, Hong Kong, Taiwan, all over Europe and a few places inbetween.

Do I really need a quad-band phone or will a tri-band (850/1800/1900) really be just fine?

Also, I am all about good reception and to a lesser extent, texting. All other things are fluff. Am I in the right neighborhood if I consider the Nokia 6102i?

I'm not sure about Western Europe, but in Eastern Europe most operators only use 1800 in cities, and once you leave the city you're done for.
Some carriers don't even cover the city that well with 1800 (Belgrade comes to mind)
-A

All of Europe was built on GSM900 first, from 1994 onwards. GSM1800 (originally called DCS) wasn't started till a couple of years later. Coverage in many European countries will be pretty much exactly the same on a GSM900 network as on a GSM1800 network, and almost all networks that started on GSM900 now also operate GSM1800 towers.

As the previous poster said; in countries where GSM1800 isn't as recent you may find yourself without coverage in rural areas.

Here are 2 examples:

O2 Germany (1800 only): http://www.gsmworld.com/cgi-bin/ni_map.pl?cc=de&net=vi
Vodafone Germany (900/1800): http://www.gsmworld.com/cgi-bin/ni_map.pl?cc=de&net=ma

I've always found this T-Mobile page (http://www.t-mobile.com/International/RoamingOverview.aspx?tp=Inl_Tab_RoamWorldwide) helpful, since my PocketPC phone only has one international band. Select the country and then choose "View a detailed coverage map" That page will show each carrier (only the ones that TMobile roams with), their operating band, and links to coverage maps for each of the carriers.

It seems like countries like Turkey and Egypt use more 900 MHz GSM.

But even in the UK, some carriers still use 900 MHz, like Vodafone.

If you can accept that your phone that does not use 900 MHz will work in many/most places with many but not all carriers, then go with it.

Personally, I use my 900-1800-1900 MHz phone outside the USA and on TMO prepaid in the USA.

But I also have another phone that has 850-1900 MHz that I use in the USA when I feel like using it.

From experience this year, looks like large chunks of India are on 900 too. GSMWorld.com has coverage maps by country listing frequencies, fwiw. Not too far off reality on the ground.

India, Africa and just about any developing country is going to be 900 only. I don't believe there are any countries that 1800 only. So, if you are looking for an international phone in the US then, as a minimum you need one that supports either of the US GSM frequencies + 900 for the rest of the world.

After spendindg alot of time trying to answer the same questions myself I realized the quad band phones are about the same price and elimate the coverage issues. I prefer 2 quad band phones so I can use a local sim card and my us phone number at the same time. Since both phones are the same model (V180 Motorola) they share the same accessories to keep packing light. I am not recommending the phone itself but definitely a quad band over the tri band. If you do go the tri band route they do offer some that have 900/1800 and only one of the US bands mostly likey 1900.