I think 20 mins at 1-2 slides/minute is about the perfect presentation time. Forces speakers to be concise; a talk is only a summary, not a detailed explanation of every single little point. 45 mins is about as long as most people can concentrate at a stretch. I never understand these 100+ slides presentations that I see at Slideshare. - Neil Saunders

I'd like to try all kinds of things at conferences and even routine labmeetings -- brainstorming, speedgeeking, pecha kucha -- but every time I suggest anything remotely new I get shut down. - Bill Hooker

I used to have the same idea (1-2 slides/minute), until I heard Larry Lessig talk. He uses a lot of slides, often with just one word on them, and can go through them quickly. But then not everyone is Larry Lessig :) - Deepak

I actually just spent a fair bit of this past weekend attempting to fix my death by powerpoint habit. I have done pretty well. Neil - Apparently it is about 10 minutes one can concentrate effectively during a powerpoint presentation. - Mitchell J Stanton-Cook

Lessig -> They call that video, not? - Egon Willighagen

It feels like I always have about fifty slides. Doesn't matter how long the talk is. Ten minutes? Fifty slides. :) - Andrew Walkingshaw

I've seen presentations where they basically cut the figures out of their paper and made a slide out of each. It was way too busy and hard to follow. I don't know if that means that their figures were too busy to start with or what, but it was so boring. I felt like they didn't even need to be up there, and everyone was reading the figure legend instead of listening to the presenter. On the other hard, for a scientific presentation, you do have to show actual data, so you can't go too minimalistic. - Mr. Gunn

I also like a lot Lessig's style. I tried it once in a talk about open science. I think it works best for presenting one concept but I don't think it works so well for detailed scientific results (although some try to flash a lot of westerns at you but it is not the same ;) Dick Hardt's talk on Identity 2.0 is another good example of this style (http://identity20.com/media/OS...). - Pedro Beltrao

from an audience point of view, the best is to end it quick and see other angles during the discussion, it is just not 'polite' to talk too much without interaction - Attila Csordas

I learned in teaching class that people only have a 10 minute attention span, and if you need to give a talk that's longer than 10 minutes, you need to do something (anything!) after every ten minutes to recharge the audience. In our examples they were mostly little exercises, but that was for students. I guess a mid-talk question round would work too. - Eva

Something I like about Lessig's style is that it demands attention from the audience. There's a new chunk of information every few seconds, and as an audience member you always know exactly where your attention ought to be. It's almost flow-inducing, although it can be a bit draining (agree with Eva - a break every 10 minutes is good). Tough to pull off a talk in this style, though. - Michael Nielsen

Hey, I know that Lessig is cool and can handle the remote well but we need scientific presenter heroes, who and where are they? - Attila Csordas