usually an extra shirt/pants, box of granola bars, my nancy caroline medic book... the brady books on top of that because the caroline books suck... and a starwars novel.
Usually bring a backpack with me to the squad, extra clothes, laptop, iPod, Purell sanitizer, a book (The Lost Symbol), an a folder for papers & such and other little random stuff.
Meh... Anyways.
Netbook and charger, Kindle, Zune, flip guides (ALS and pharm). Cables for Zune and Kindle and charger for HTC Hero. Metal water bottle, vacuum flask. I'm used to being in a bus for 12-16 hours. Never worked out of a station
in my EMS bag, I have my dept issue jacket, helmet, wacker belt, leather gloves, scope, and boston leather style webbing radio holster. all this stuff stays in my truck 24/7, and gets taken with me into the ambulance during my shifts.
I also will take my laptop with me, depending on where I am working, and how busy I expect it to be.