Quote Originally Posted by Syrokko View Post
This is a good idea...
But...
Cell phone connections are quite easily compromised when connected online.

You might even be putting your account at risk if the security is not heavy enough.
That said, banking/paypal apps seem to work without any security faults (knock on wood >_>), so I guess it wouldn't be too difficult to develop a piece of software capable of providing security whilst protecting itself against any threats.
The main way of compromising the data on a phone, is not with it being online it's Bluetooth, Bluetooth has virtually no security so if someone's phone has it's Bluetooth switched on it is easily compromised, I believe it is even possible when your Bluetooth is not discoverable, that is why it should be switched off when not in use.