I'm sure this has been tried atleast once but I really want to get one going... I used to be a daily replier to this on the Virtual Hideout forums...

Here's How It Works:
You take the second word of the previous association (i.e. computer :: hacker, you would take hacker) and associate it to something... be creative and try to just post associations, keep comments tiny so that this turns out well and try to use the format word1 :: word2..

I'll start it with:

man :: woman