Oh, you want more explanation than that?
Well ... you could be in awe of the fact that I was on stage with Jonathan Coulton, but honestly that makes it sound a little more awesome than it was (well, it was awesome as in totally cool, but perhaps not as in to inspire awe).
If you really must know, Jonathan Coulton encouraged us all in the audience to sing along with the "all we want to do is eat your brains" line, and then said while he appreciated that we all sang well, zombies wouldn't--in fact they might not really be able to speak at all, and they'd probably move around, fast or slow, and that he encouraged us to do anything short of coming up to him after the show and biting him. So, I believe that got cogs spinning in Evo Terra's brain, and he leaned over to me, and then to two others, and said, "next time, we're going up the stairs [onto the stage]". So, um, yeah, we did, and fake-attacked Mr. Coulton in a brain-eating zombie sort of way while he was singing the final lines of the song.
As I turned to return to the floor in front of the stage, I succeeded in falling over, twisting my ankle extremely badly. I thought it was going to break. Horribly embarassing too. For all I know, as this was a small crowd of podcasters and bloggers and the like from New Media Expo at a really informal sort of concert thingy (not just Coulton; a number of acts including Dan Klass as MC, The Radio Adventures of Dr. Floyd, Natalie Gelman, Chance & the Choir and Richard Cheese & Lounge Against the Machine -- though we left during that last act), this may be up on YouTube already.
[Edit] It may not have been then ... but it is now! It seems inimitable J.C. Hutchins posted a blog post about the zombie invasion on MINE, including an embedded video from YouTube of the terrible (and terribly awesome) event! Naturally, he also tweeted about it.
I was ok for a couple of days and then when I got back from Vegas, after the day or airports and planes, it was seriously painful, swollen and I could no longer really walk on it. I went to see a podiatrist today, got x-rays done (no break/fracture, only a bad sprain), and he gave me a boot which now allows me to walk! Yay!