What's a good topic for a technical presentation?
frossie: Lunchtime? As in, people are eating? The sleep risk is real with those. War stories, whether they had a happy ending ("I fixed it") or not ("I learned from it"). If you don't have your own, you can walk though someone else's provided enough technical information is available - for example the lost NASA Mars Rover is a good way to explain race conditions, depending on your audience.