This is one for the older BYONDers (i.e., those of us who have jobs). It's now fifteen years old; I probably first read it sometime around the time I found BYOND (1999), but it strikes me that it's still a neat idea today. Sure, you could just use AIM or Trillian to communicate with co-workers in other locations -- but why do that when you could use a BYOND world, and bash their heads in with a sledgehammer when they interrupt your web-surfing?
"Collaborative Networked Communication: MUDs as Systems Tools"
Interesting side note: I posted this today because I saw the name "Denali" in the news, and that word (along with "squirrel", "MUD", and "unreachable") is one of the mental keywords I chose to make sure I could find the article again in the future. I once read a good article about a program that would scan a web page and identify four or five keywords that would produce the desired page as one of the top hits in a web search -- but ironically, I don't remember the key words for that article. I'll let you know if I find it.