I'm having a difficult time figuring out the best way to do this. Feel free to explain as if I know absolutely nothing!

In March, I am going to Amsterdam, Berlin, Frankfurt, Beijing and Shanghai. I would like to have a phone in all of these places. Calling and texting isn't really as important as data for things like maps and translation (I speak none of the languages in those places). I have an S3 on Verizon, which has an upgrade available, but the way I understand it, the Verizon S3 is not a global phone for data anyway.

Should I buy a non Verizon unlocked phone on ebay? Will I then be able to buy a SIM card in each of these countries? Any recommendations for a phone that won't cost much but is still usable? Will buying a SIM card be difficult for some reason? Any help is appreciated.

I also have a Verizon S3 with which I've traveled extensively (after unlocking it... not so hard). If I were to buy a new phone in the US now, I'd probably opt for a carrier neutral Nexus 5.

Depending on how savy you are, you can get your Verizon S3 working on GSM networks outside of the US. It is unlocked for international GSM use (but still locked for US GSM carriers) and has a Micro SIM slot and support for the following bands:

- SM/GPRS/EDGE 850, 900, 1800, 1900 MHz
- 3G UMTS/HSPA+ (21 Mbps down, 5.76 Mbps up) 850, 1900, 2100 MHz
- 4G LTE 700, 1700 (AWS) MHz.

The issue is that Verizon and Samsung have disabled the ability to change/program the APN for the network you're on. This means it's likely that by inserting a local SIM into the phone you'll only get Voice and SMS but no Data. The workaround it to root your phone, install an app like HiAPN, use Titanium Backup to make that app a System App, and then change/program the APN for the local carrier. I'm not sure if other Verizon Android phones with "Global" support require you to jump through the same hoops.

An easier alternative might be to pick up a Motorola Moto G (Global Version) for $180 (Amazon) for use on your trip. After the trip you can keep it for future travels or sell it on for very little loss (and maybe even a profit based on current eBay prices). Now you can just slide in the local sim for the country you're in (or use something like OneSIM for the whole trip) and you're off and running.

If you do buy a Global Moto G and decide to sell it after your trip, PM me

I have a Microsoft friend who will give me one of his old Windows phones (probably some version of a Lumia). Any issues with trying to use a Windows phone?

So just to confirm, I have the right basic idea on all this? Obtain a GSM capable phone and buy SIM cards as I go? Is it possible for me to get one in Amsterdam that would work in Germany or would those have to be separate?

With OneSIM you could get a single card that would work in all of your listed countries, you just need to check the rates and supported networks in each to see if it's a good fit for you.

Otherwise, you can get a local sim in each country. Others can comment on a good single-sim option for both the Netherlands and Germany, but I would suspect there is something that will work in both for a reasonable price.

As for the Windows Phone, as long as it's SIM Unlocked and supports the bands necessary (likely) then you should be good to go.