an easy way to save on the internet data

i recently observed that when the internet is left on, there is almost always some data transfer going on. in order to curb this i tried something which worked pretty well. i created a dummy data packet account and whenever i didn't want the phone to connect to the internet (eg, in cases where some games or apps need u to be connected so that they can run an ad near the bottom of the app) i just simply select the dummy account. now there is no info to the phone about where to connect to in order to have any active data transfer.
here's how u can create a dummy account :
applications>settings>wireless and network>mobile network>access point names> new apn(by touching left options key)> edit name and any details it prompts with "nothing" (i used "nothing", u are free to to use any word u want), then save it in the end.
whenever u wish to disable the internet data transfer, u can always select this "nothing" account.
if you have any other idea to save on the data transfer, please do share. thanks.

have fun