More a post, to share my experience as the question has been asked over and over. I imported an unlocked Verizon pro via ebay from the USA. And am happy to announce it is fully functional on O2 in every way including OTA updates to gingerbread 
Had some fun setting the APN settings but had help from my UK Defy
the only issue I have had is the same as everyone else shite battery, BUT I've ordered the extended life one from the states and messed about with the settings but will get there eventually. The problem is you have to pick GSM &UMTS mode in settings as CDMA doesn't work in the UK and GLOBAL doesn't let you use 3G!! This drains the battery as its always looking for a 3G signal! Still its a great phone so all worth it
Had some fun setting the APN settings but had help from my UK Defy
the only issue I have had is the same as everyone else shite battery, BUT I've ordered the extended life one from the states and messed about with the settings but will get there eventually. The problem is you have to pick GSM &UMTS mode in settings as CDMA doesn't work in the UK and GLOBAL doesn't let you use 3G!! This drains the battery as its always looking for a 3G signal! Still its a great phone so all worth it
