DrupalCon was held recently in Barcelona. I didn't make it this year. the schedule looked good though, and from all reports it was the best drupalcon ever (as it is each year!!). there's a wrap up post on the drupal site with links to some of the slide presentations, videos of the sessions on archive.org - search for drupalconbarcelona2007 tag, or try the mirror site.
drupal for facebook was a session by Dave Cohen. he's started a Facebook project on the Drupal site. the video of his presentation is online as well as the slides
there's a demo on facebook. I'm already feeding facebook with my drupal site blog entries using the RSS capabilities of Blog Friends and the built in Notes application, but it'll be interesting to see what the Drupal guys build.