I got Disney lanyards at Party City for a dollar last week. They have Toy Story, Mickey Mouse, Tinkerbell, and Princesses. There are a couple other characters too, and they are a little thinner than some but I think they will work great!
I found mine on eBay. They cost about $4 each, including shipping. Got Minnie, Daisy, Princesses and Toy Story (for DH b/c we just can't get him to wear princesses, even if he is a dad of two girls! )
I found one on Ebay for $1.19. It is really nice and came from Hong Kong. We decorated our lanyards tonight w pins I bought on ebay as well and we are ready and set to go!