A couple of interviews in which Steve talks about his approach to usability testing, with lots of hints and tips. The biggest area of interest to me was around raising awareness, buy in and support for this kind of activity.
After all, there's not a lot of point doing tests if nobody watches them or takes action on what you uncover.
A lot of this is covered in his latest book - Rocket Surgery Made Easy - but if you haven't read it, this is a good place to start.
Steve Krug on DIY usability testing .net magazine interview
Steve Krug applies common sense to UX - podcast interview and session summary on johnnyholland.com