IPhones: iMessaging people in other countries?

I was wondering if it costs anything to text message people in other countries that also have iPhones (iMessaging)? Like if I, in the USA, texted someone in Australia who also has an iphone?

If it is exclusively through Apple's iMessage system (be sure you're using iMessage and that they are), then it shouldn't cost anything extra for overseas texting.

Yes it would work. Any product that has to do with apple has imessage. So yes even if that person is in Australia, you would be able to text them. As long as their device is connected to internet, 3G, E, or Wi-Fi, you and the other person will be fine