ok, you post a word, a simple one like cat. The next person posts a word that is in some way associated with the last word (include an explination if needed) like dog.
To make it interesting, anyone at any time can switch it from association to disassociation. In which you have to think of a word that has nothing to do with the last. For instance if someone posts cat, you could post fudge. (but, dont go crazy and saying things like: "my cat eats fudge!")
Its pointless... but fun.i will start.