I have an unlocked captivate and am travelling to Germany and Switzerland. I have a German T-D1 pay-as-you-go sim that I've used many times in unlocked GPS phones. Now I have an AT&T captivate and wonder whether GPS or other apps will work. Does GPS require a data plan to work? If so I'll have to figure out whtehter I can add this to my T-D1 plan. This will also answer my question about whether using the Captivate for navigation in the US needs a data plan to work. Thanks!