For those telecom types out there:
http://www.parse.com/free/analyze_dtmf.html
contains an 8-band filter that analyzes DTMF digits within .wav files.
YMMV 
Cheers,
-RK
–
Robert Krten, PARSE Software Devices +1 613 599 8316.
Realtime Systems Architecture, Books, Video-based and Instructor-led
Training and Consulting at www.parse.com.
Email my initials at parse dot com.