Originally Posted by ck7ah
My wife got a HTC Desire S at the weekend, and in 1 days she has used 50MB of data. She just downloaded a few apps, browsed FB and added her contacts.
As she is new to Android phones, how can we ensure that nothing else is on using data whilst the phone is idle?
First of all, deactivate Mobile Network on your phone.
And to be 100% sure, check, that no applications are set to auto update, else it's possible, that anytime you manualy turn on mobile networking (to browse facebook or whatsoever) you "waste" data on updates.
settings > Wireless & networks > deactivate Mobile network
settings > Accounts & sync > uncheck Background data and Auto-sync
hope that helped