Short talks on a topic that's interesting but not enough to talk 45 minutes about e.g. "here is an nice debugging trick I use" or "this is a tool I've been evaluating recently" or "did you didn't know you could do X in Javascript"
There is a time limit - 8 minutes max, including hooking up your laptop at the start and questions after.
If you need slides, less is more plus keep them in portable form (if connecting to the beamer is a problem)
You can turn up with a talk on the evening - no need to announce up front (although you can if you want to below)