Controlling Arduino via cellphone

Hi all

I an trying to figure out how to connect a cellphone to Arduino in a way such that I can give input to Arduino by generating DTMF tones from a remote phone.

In other words: - Phone A would call phone B; - Phone B would be connected to Arduino. - Any DTMF sound generated by pressing keys on Phone A, and - would then be received by Phone B, and then be translated into signals given as input to Arduino.

Any suggestions?

Than ks