Some time ago (from memory) I believe there was a page on the Vodafone site that if you were planning on going somewhere, you could select the destination and your handset from a list, and it would confirm if your phone would work in that location or not, and if you could access 3G, 4G, etc.

I checked the site tonight but can't find it anywhere - does it still exist or has it been moved? I searched through the Roaming section but couldn't find anything.