(Not really operations but this is my least-inappropriate gridpp blog for this...)
I was invited by Lambeth City Learning Centre (www.lambethclc.org.uk) to give a talk about "computing and science" to schoolchildren. They were 14 year olds, it's the first time I've given talks to children.
My first main point was that increases in computing performance enables researchers in every single field of research to do more, particularly in a world where now everybody needs to collaborate. I used the grids as an example, talking about GridPP and NGS. Only one of them had heard of LHC (or would admit to it).
I used games as an analogy - they all knew those. Games visualise a world which lives inside the machine, they "collaborate" by playing with others.
The other main point I made was that they need to think. The computer is stupid, it doesn't know that it's flying a concorde, calculating the length of a bridge, or folding proteins. I gave some examples of datasets in many everyday contexts which say one thing by themselves but say something very different when you think more carefully about the data and put it in context, both historic examples and very recent ones from the news.
I definitely enjoyed giving the talk (it had been buzzing in my mind for over a month). I think they enjoyed it, too, although I was slightly worried some topics were too adult - I was also talking about computers doing epidemiology, emergency medicine, and nuclear weapons maintenance, the point being they're safer to do inside the computer than outside.
Curiously I had understood they were all girls so I had looked up quotations from women astronauts etc. What turns up on the day? Boys, every last one o'them.