My good friend and Dead of Night contributor, James Mullen (he of the excellent Cold Fusion scenario in the second edition book and of a guest post on running a Dead of Night campaign on this very site) has started a new website, Groundhoggoth, which he describes as a “lair of good games.”
Amongst the many homebrewed micro games (many of them quite delicious) and scenarios is James’ pseudo-LARP Dead of Night scenario inspired by the The Mist. Now, whilst I’ve not had the pleasure of playing the scenario for myself, I’ve heard many a scare story about it so can recommend purely on that basis.
And whilst you’re over at James’ site, make sure you check out some of his other games – I particularly recommend Never to Die, which is best described as a “chav dungeon crawl.” Need I say more.
Steampower Publishing 
Having played this Mist scenario at Conception 2010 I can highly recommend it to all.
How did it go? I’ve not had the chance to try it yet, but hopefully James will run it next Conception (hint hint).
The two problems are that 1) I don’t like running the same scenario again at the same convention and 2) we almost set off a terror alert last time. I’m tempted to do another pseudo-LARP, so the same style but a different story, but that still leaves Problem 2!
How did you nearly set off a terror alert?!
It was my crazy pseudo-LARP idea, which caused someone to approah the bar/kitchen staff over the course of 5-10 minutes and ask this series of questions:
“Are your stoves gas or electric?”
“What happens to the gas if the power goes out, does it switch off automatically?”
“Where are the fire extinguishers?”