Yes, they sell t-shirts with the year and some cute halloween scene with the party name on it. They are usually very cute. Also, each night of the party, they release a pin for the party with a different character on it. The pins are available at the party first, but I believe they are also on sale after the party in the stores. I know they are limited and I think one place we have bought them is on Main Street, the big store, and I think in Frontierland. Info should be on the map/brochure they pass out on the nights of the party.
We always buy the pin that is released the night of the party we go to…makes a great keepsake!