At the Writing About Testing Conference I gave a lightning talk on how to give a lightning talk.
I adore lightning talks. They're a great format for beginning presenters, because you get a nice round of applause if things go reasonably well, and you're off the stage in less than five minutes if they don't. They're great for experienced presenters, because you can field concepts without having to prepare a full-on presentation slot. Finally, they're great for audiences because they're information-dense: they pack 10 to 12 new ideas into a single hour of conference time.