Windows Mobile had some kind of minimal data mode that worked very well.

I don't remember the specifics, but do I know that with WM I used less than 10Mb a month roaming abroad, without doing anything special. I was just using a dedicated email address so I might send email if needed, but not receive all the crap and attached files I usually get.

I was shocked when I moved to IOS and couldn't make it consume less than 20x as much per month.