i think it could be usefull with an app that automaticly switches between gsm and 3g when ever you start data roaming to go online on the internet.

If you are not online on your phone, theres no reason that the phone is on the 3g network, since its a huge power consumer, and drains battery alot faster then gsm/edge.

So with an app that actives 3g automaticly when you start data roaming, and switches 3g off again when you close the connection could be quite popular.

Tell me what you think.