[avolcoff]

I would like to commnuicate between two mobile phones over DTMF.

How do I listen for incoming DTMF Tones and convert them to a String ?
(I already know how to send DTMF Tones)

Can you show me the appropriate API or Code Sample ?

[simon.hain]

afaik there is no possibility to do so.

[Dan East]

You would have to process the audio at a low-level within your application. The algorithm you'd be interested in is the fast fourier transformation. However, if you have to process the audio manually, it would probably be easier to implement some sort of simple pulsed audio (think of really fast morse code) instead of DTMF.