yes – this is what that little software tool I posted before is used to avoid.
Basically it turns off 3G use for data etc. – easy control for toggle 3G on and off (which is otherwise a registry rewrite and complex for many users to do).
This works on HTC, Dopod and I understand any Windows PDA actually.
Thought good to mention here and point out that it is equally as useful, for those who do not want to use 3G data even when at home.