I've been wanting to do this for a long time, so here goes. I'd be curious to see what others use their quickchat slots for.

Post below what you have in them right now or funny/useful/memorable stuff you used to have in the past.

Here are a few of mine:

/hostinfo (so useful!)
Wait :) (for stronghold roundups)
Run orb (ah, remember those days?)
Kill totem
Heading to the mall...
/r from a forum contest (I knew I'd need this a lot after I got the PL shield; also /r not tradeable)
:) (a good reply to everything from "Ty for rez" to "good to see ya", so you don't have to get killed typing a response)
/t [friend name] ... (a quick way to check if a friend is online without looking at your friends list)
/team behind u (very useful for Underground!).