We too bring a small softsided case of wipes (usually w/ a Disney theme!) along w/ the purel. Soooo many times the wipes work better than the Purel...and then you finish off w/ the purel to sanitize.
ALWAYS bring a nightlight w/ us and a backup bulb! just gives a little glow w/out having to have the bathroom light on. Helps the kids to feel more comfortable in a strange room when they can make out the other bed w/ Mommy & Daddy in it.
We bring a few trader pins in a ziplock bag in our pockets for each day. Easy to see and get to w/out the chafing of the lanyard around the neck.
I know I'm in the minority, but I can't stand fanny packs.

They get me all sweaty around the waist, no matter how loosely I think they're hanging. I carry a purse that has a lot of compartments built into it's lining and flap. A sport for my license and a few cards...a safe zipper section for extra money, a decent size lined middle for a couple of drinks and snacks. The outside pockets hold my cell phone, sun glasses and passes so I can whip them out quickly and get FPs. It cost me $10 at Target and I love it! Days when we take the video camera it fits inside too. It has a thicker soft strap than most pocket books and looks more like a camera bag so DH doesn't mind carrying it occassionaly either (when it has the heavier camcorder in it. Otherwise, I'm fine w/ it.
We make a grocery stop on the way to the hotel and always buy a box of nice soft kleenex as it makes such a difference.

We get OJ, Apple Juice boxes, gogurts, that sort of thing that we didn't want to pack in our suitcases.
Bring light sticks from home. And here's a tip.....if you have a fridge in your room, put the light stick in the small freezer section when you return at night. It will last for 2 or 3 nights. When you 1st take it out it is so cold it barely glows, but as it warms up in your hands...and you shake it around...voila! It works again. The kids think it is Disney magic.
Let your kids take some pictures. My son started when he was 5 and sure, some are a little blurry, but most came out pretty darn good. And they're from a diff't perspective. We give each one a disposable camera...and then later in the trip, I started letting him take pics w/ our digital camera too as he was so careful.