[NTLUG:Discuss] how can I copy the last 'x' minutes of a MP3 file?

[Jack Snodgrass]

   I have a bunch of MP3 files ( WBAP radio station 6am - 8am ) 
that I want to batch crop and get the last 7 minutes or so and 
put into a smaller MP3 files. 

   Does anyone know how I can easily and quickly ( don't want 
to play for 53 minutes and then 'record' the last 7 minutes to 
a new file ) get the last 7 minutes of the file into another
MP3 file? I'd like something I can run from a script or the 
command line. 

Thanks - jack