I made a pitch for the last Wikimedia UK AGM:

"I would like to facilitate a session or sessions of lightning talks, like those I participated in at GLAMsterdam (see my blog post on the topic http://pigsonthewing.org.uk/lightning-talks/ which explains the process and rationale). Any attendee can have, say, one minute or so (to be determined) to speak to everyone present, on any Wikimedia-related topic. Timing can be flexible, so this can fill gaps between more structured sessions. Also useful in case of under-runs, or planned speaker's not attending."

I'm not going to pitch it /as a session/ for Wikimania, but I would like to see such slots included (they could be allocated by drawing lots). It's key that such presentations are to the whole audience, say at plenary times, and they're a good, flexible way to fill any dead time or to build in slack ("you get to speak, unless we're running late").

I'd suggest slots of one minute (or even 30 seconds) each would be right for this size of event.