You may want to disable the automatic software updates checks that occur upon internet connection, in order to consume less bandwidth when using 2G/3G connections.

You can do so by editing the gconf file found in /var/lib/gconf/apps/hildon/update-notifier and changing the check interval from 1440 (24 hours) to a much larger value. The value must not exceed 4,294,967,295.

Via : wiki.maemo.org