There is no simple solution :)
For me, a big factor in my "Travel with old 9810" is work email. BES10 is still being piloted at work so it is not fully functional. People at work often send multiple iterations of large powerpoint files of 20mb + in size. I have no way to control how much attachment is downloaded on Z10. One such email can eat up my data quota for the whole trip.
Posted via CB10