I'll be in Europe for 2 weeks starting this coming Monday (France, Italy, Spain, and Portugal). I'll be taking my iPhone 4 with me, not to use as a phone but to use for email & internet when I'm on wifi.
I think I can just flip all the cell services off in the settings... but I'm not sure. Does anybody have experience with this? Anybody know exactly what I need to do to avoid roaming charges?