FYI on option 2. If you put the phone in Airplane Mode (and leave it there) and turn WiFi ON, you can use web, email and most apps (no SMS texting, but iMessage will work with iPhone users over WiFi).
In Airplane Mode, the GPS chip is turned OFF, but for most purposes that won't matter as you'll use your WiFi access point for location purposes. In Airplane Mode while out of the country, you'll never need to worry about any roaming charges.
If you need the built-in GPS (say for some app), you can take the phone out of Airplane Mode, but MAKE SURE that Settings > General > Network > Cellular Data is OFF and that Settings > General > Network > Roaming > Voice and Data Roaming are OFF. The phone will search for a network, won't find one, but the internal GPS chip will work.
If you need SMS texting, look into an app like TextFree or similar.
I just returned from a month in Alberta, Canada, that's how I used my phone.
For using iPhone overseas/international you have talk with our Sprint Worldwide Care 1-888-226-7212, option 2.Yes, you can activate wifi and there are no charges for using Wi-Fi(tap Settings > Wi-Fi, then turn Wi-Fi on and choose a Wi-Fi network) to send email and browse the web while you travel international.
Hope this helps
I am travelling to Europe in September and I'd like to use my iPhone, but not at Sprint prices. Is it possible to unblock the phone and put a different sim card in? Also, if I can't or don't do that, is it possible to use wifi for email and web access without paying extra money to Sprint? Thanks in advance