On: go to xkcd.com: The webcomic XKCD now has a comman...

[blahedo]

And if you go back to the start and then go south:

   A dark hallway.

   Exits: north, south
   You are eaten by a grue.
   You're dead!

:)

[warfangle → blahedo]

And if you say

light lamp

before you go south, you don't get eaten :)