great information resource, thank you very much!
Originally Posted by lekky
If you have both WiFi and data connections turned on, your phone will default to using the WiFi connection as long as you are connected to a WiFi network. So no need to turn mobile data off using home WiFi.
Unfortunately for my HTC Desire supplied by Three this is not the case. Their technical support dept has told me that I need to manually switch off the Mobile Internet in order to use WiFi. I wish you were correct here!