I unlocked the radio on my D2G and tested it while in Kazakhstan using a Russian Beeline SIM. Everything seemed to work well, but I forgot to test SMS. It also worked here in the US with an At&T SIM. Follow these two links for the full how-to.
My Experience Of Gsm Band Unlock--Worked On 330 To Gb - RootzWiki
TBH US GSM Band Unlock for Droid 2 Global and Pro Update.zip Public Release - Page 3