I've already started packing for the trip, although I'll probably re-pack and re-organize my stuff several times between now and when I actually leave for the airport. My race day clothes are picked out and ready to put in my carry-on, along with a backup outfit just in case. My Disney park pass "will call" confirmation is printed out in triplicate, and with copies stored in my wallet, my carry-on and my suitcase, again "just in case". I've printed out two copies of my marathon waiver, packed my iPod charger and Blackberry charger, and am charging up my camera batteries as I type this. My plan is to take both my iPod Nano and iPod Shuffle with my Nike+ Sportband as my "Plan B".
I know I've over-packed some clothes, and I'll be narrowing them down within the next few days, so that I have two outfits for each day of my trip - one warm weather outfit, and one for chillier weather. I have a set of "dispose-a-clothes" to wear in the chillier early-morning temps on race day while I wait for the race to start. I have a checklist a half a mile long to make sure I don't forget anything. I think I'll relax once I'm actually in the airport with the rest of my team!