Good news for D2G users who travel outside North America! You no longer have to use the incredibly expensive VZW/Vodaphone SIM card. Last year, I had my phone unlocked prior to a trip to Russia. [You're entitled to unlock your phone (and SIM card) 60 days after you purchased it, and can do that up to four times per year on your account, meaning you can unlock up to four phones.]
When I got to Russia, I bought a MTS SIM card, plugged it into my phone and voila...nada! I couldn't send or receive calls. Back to the drawing board. During the year, I rooted my phone and subsequently unlocked its GSM radio (see links My Experience Of Gsm Band Unlock--Worked On 330 To Gb - RootzWiki and TBH US GSM Band Unlock for Droid 2 Global and Pro Update.zip Public Release - MyDroidWorld.
This time I went to Kazakhstan and while there borrowed a friends Deutsche-Telekom SIM card, inserted it into my D2G and...TA DA! It worked! I could both send and receive. It seems that I forgot that many of the GSM providers in the rest of the world (except Vodaphone) use the two GSM bands that VZW blocks on the D2G. Anyway, all is working well both here and overseas, without having to use the incredibly expensive Vodaphone SIM card. By the way, I did not test it for data, but I imagine that is only a matter of purchasing the right plan from the overseas GSM provider.
Good Luck and Sheslivovo Putie!