As part of a lightning talk, I did a lightning talk at a Drupal Meetup in LA on the Field Collection module for Drupal 7. For those that do not know, Field Collection is a successor to the multigroup module in CCK from Drupal 6. It allows a user to associate a grouping of fields as one field to for any type of entity (including another field collection so you can have nested field groupings inside other field groupings). I had done this presentation in a very inpromptu manner (set up a site for demo purposes) and hopefully you get something valuable out of it :) The presentation was with precreated field collections so the audience could see how it all works (as opposed to seeing the creation side of it) and I'm planning on fleshing this out so there is a full-fledged presentation on the module.
Below is the presentation: