i did a presentation for the 7th umeet conference. best part was that i didn't have to change out of my jammies to do it since it's an online conference held on irc. no travel time, no huge impositions on my schedule ... perfect! =) i "spoke" about kde4, generally working off my kde4 presentation slides.
they have a really nice line up of speakers from all over the world this year. rik van riel opened things up on tuesday, duncan mac-vicar will be speaking on sunday about kopete and rms will be speaking tuesday. the presentations are interactive: you can ask questions in the questions channel and the speaker answers them at their leisure and discretion. they post irc logs and slides (if any) on the site so you can read them whenever.
i look forward to next year's umeet when i can talk about the upcoming kde 4.1 ;)