No worries.... I think mines may be a 26"suitcase (with wheels) that I'm bringing. (I know that isn't considered carry-on size) I talked to a guy who went on this trip 2 years ago and he told me he took a bigger suitcase with no problem...just as long as your're able to lug it around yourself and keep up with the group.
One good suggestion he gave - pack small packages of snacks that you like in your suitcase for when you get the munchies. (Anyone with nut allergies in our group?)
I've used these "compression bags" before and they work well. They're available at REI, Bed Bath and Beyond, and many other places.
http://www.rei.com/product/739705
See everyone on Friday!
Joe