Pecha Kucha is usually pronounced in three syllables as "pe-chak-cha", is the onomatopoeic Japanese word for the sound of conversation. The equivalent English term is "chit-chat". This presentation format was devised in 2003 in Tokyo.
The idea is simple: you have 20 slides and each one is shown for 20 seconds. The slides are advanced automatically, and at the end of 6 minutes and 40 seconds you shut up because you are finished.
Building a pecha kucha presentation is easy—just have 20 slides and set the auto advance to 20 seconds. The content of the slide is limited. I suggest that you completely abandon bullet points. These hideous things are really of little help in getting ideas across. Instead, look for images and diagrams that you can explain in 20 seconds. Go back over your presentation and remove any element that does not add value to what you are saying.
I strongly suggest that you use paper and pencil to sketch out your presentation before launching Keynote of PowerPoint. You only have 6:40, make sure you are talking about one good idea, and not trying to discuss several unrelated topics.
You can get samples of pecha kucha presentations on the web. And I would also recommend visiting Garr Reynolds site for pointers on slide content.
— James Robertson email@example.com