If you have to wait, find fun portable stuff that will fit in a back pack, which can be taken on the rides. I would not suggest this on Kali River Rapids however, as your stuff is likely to be drenched.
Let each kid pack "line stuff" in their own backpack, or have them pair up and share a back pack if you have multiple children. Here are some ideas:
Hand held video games
Portable DVD player or video player
iPod
Mad Libs (remember these!?)
Sing songs
Disney trivia
Puzzle books (crossword, word search, logic, etc)
Map out game plans for the next day or what to do later that day
Word games
Charades
Rock Paper Scissors
Read books or magazines
Some of these you are likely to get people around you to play to make it even more fun.