It's an oldie, so many of you have probably seen it already: the Dynamic Languages Wizards Series, Spring 2001, hosted by Greg Sullivan and Jonathan Bachrach, of Dylan and Goo fame.
It's a series of three panels held at MIT, discussing dynamic languages in a joyful and challenging atmosphere. All three are great, but I like the first one best, on dynlang runtimes. Richard Kelsey (Scheme 48), David Moon (all around wizard), Tucker Withington (Harlequin), Kim Barrett (embedded guy), and Scott McKay (all around wizard) are a great and funny tag team.
Moon is up to great PL design work with the Programming Language for Old Timers (aka MUD – Moon's Ultimate Distraction) nowadays.