In this rare interview from 2006, the boys discuss the art of podcasting.
There's not much information available for this recording, however, after a bit of research I can tell you that it's from a podcast called "PRI's The World: Technology Podcast" hosted by a little American fella called Clark Boyd. At one point, Clark plays a short clip from series 1 episode 11, referring to it as "last week's episode", so this podcast would have been released sometime around 20 February 2006.
NOTE: For some reason, the YouTube version of this podcast features an intro outtake then 45 seconds of silence. This has been corrected in the MP3 download.