iMessage isn’t only free within the US – it’s free across continents. An international data plan can be expensive and texts can cause fees to skyrocket. But for iOS 5 users, iMessage can help avoid unnecessary charges. If you're the one abroad, make sure that you are connected to Wi-Fi. (Also remember that Wi-Fi is not necessarily free. There may be fees attached on that end.)
If those blue text bubbles suddenly turn green , that means your phone is starting to send an SMS messages. This can be avoided by going into Messages, under General Settings, and turning off Send As SMS.
iMessaging is free internationally – just as long as Internet is.
