During next Maemo Summit we will have at least 2 hours (one on saturday and another one on sunday) of lightning talks, about 20 talks where people will try to explain or present something in just 5 minutes.
Last year, during Maemo Summit 2008, I did a lightning talk too and I must admit: even if I knew a lot about the subject of my talk and even if I had already done many other talks, I think it wasn't so good as I expected.
This year I've been selected again (more details will follow) to give a 5 minutes talk and with this great news the kind Dave Neary also suggested me a link with an article about some best practices when giving lightning talks. I'll try to resume the most important points, hoping this will be useful for people who is going to give a short presentation at Summit.
Go straight to the point: five minutes finish sooner than you can expect. You have to talk about the main topic of your talk within the two first minutes, else you risk to talk too much about the rest and you couldn't have the time for the most important thing.
Leave details away: people will never remember too many details explained in so little time. It's better to leave them away and put them in a more detailed blog post that you can link within your slides.
Slides: for a five minute talk you can avoid preparing slides, but if this can help you to concentrate on points you have to talk about, please prepare them. Two or three slides can be useful to introduce yourself, to write any reference of what you're talking about many other things. Another important thing, make sure your slides are ready before starting your presentation: people don't want to wait 20-30 seconds it takes to start Open Office or any other similar application.
Consider any eventuality: the presentation file could be damaged (be sure to have a copy of it, better in PDF format), your laptop could have no more battery (make sure you've a copy of your slides in a USB key), aliens could take you away, ecc... (ok, this last eventuality is remote).
Concluding your talk: don't worry if you finish one or two minutes before, people won't bother about it. It's better to finish one minute before than 30 seconds later. If you want to leave an URL where people can find more details, how to contact you, put it in every slide so people will be able to take note of it from the first minute.
I hope to have resumed the most important points of the original article. If you think there are any other important things to say, please leave me a comment and I'll add them. I really hope you will enjoy Maemo Summit and its lightning talks!