Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
This feature is easily turned off though.

'Settings > Messages > Send as SMS?'

oh just ignore him, he's never happy and just argues until people give up on him.

simply put, people are not as stupid as he makes out, people will just turn things off they don't want to use when abroad and turn them on when they do. if they don't then they have no common sense.
 
It is, but then I can't send messages to people when iMessage doesn't work.

Ideally I'd be able to choose exactly when iMessage should be used and exactly when SMS should be used.

I also don't think that's how it works. When iMessage isn't working, the other person should theoretically be offline too, and therefore it would immediately fall back to texting. That's how I assume it should work anyway.
 
I wish I could easily turn off data roaming for everything except imessage.
I can still do it by turning off all email accounts etc......would just be easier to have an option data roaming on for iMessage.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.