After a quick lunch (so sunny!), Mark Fowler presented Camelbones - Perl and Cocoa. This is really about using XCode and CamelBones to write native GUI apps on Mac OS X. He went through how to create simple apps (live demos!) and showed how easy it was to click and drag and create little applications. Interface Builder looks a bit fiddly to use (why would I ever control drag?) but the Perl side was neat.
(Via Planet Perl.)