Headslap - I keep forgetting piddlepacks.  I REALLY need to add some piddle packs (Thank you - you just made the thread worthwhile)
As for "real" deployments - just the blackout, and a "partial" activation of a barge fire (got called off at the last minute).  A bunch of practice things
Quite a few of the guys I 'work' with did the WTC on 9/11 and the weeks active.  I got my license a bit late for that
Spare socks, and underware stay in my EDC bag in case I get stuck at work (I carry a 45 lb bag to/from work every day!)  Look at  
for my bag  The BIG question is what I forgot!  Not so much in the EDC bag - that has proved itself fairly well.  What I worry about is the "rest" of the stuff that gets loaded in the truck as needed.  One big problem is that like MOST folks in NYC, I take mass transit to work, so I'm stuck with ONLY the EDC until I get to the truck
I store a LOT of stuff in 5 gal pails for the truck.  If I'm in the truck I can use one of the pails as a toilet (Key a roll of paper in there <img src="images/graemlins/smile.gif" alt="" /> )  I remembered flares after the blackout, and I was given a couple by a friendly emergency worker (They got "left" in the truck)  After working in the city streets in the dark, with traffic, I now KNOW why policemen and firemen are paranoid about safety on the road (keep a parked vehicle between your work area and traffic)
The thing is, unless you are always thinking about it, you tend to "forget" things.  On a training exercise last weekend, I forgot my rain gear!  Of course, it rained  <img src="images/graemlins/frown.gif" alt="" />
Edited to fix URL