I intentionally never brought anything to keep them busy while in line....I wanted them to learn at a young age that standing in line is part of going to Disney....lol. :ROFLOL:
But in all seriousness, I understand it can be difficult for really young ones to wait in long lines. We had a rule when they were younger that if the line was longer than 20 minutes, then we were not standing in it. We became experts at using fastpass and figuring out what time of day is best for each attraction.
We usually do things in line that do not require an actual item because my kids seem to constantly drop and/or lose things, and I get annoyed at having to get things in and out of my backpack (and I also believe that *most* kids should not have to be constantly entertained once they are past the toddler stage, especially with something electronic). Sometimes we will play something like I Spy or 20 Questions (and the word for 20 questions has to be Disney related, of course!) but usually we just talk about our trip....ask the kids what their favorite part of the previous ride was, ask them what the want to do next, etc...
We also use the time in line to give them a snack and make sure they drink water (only things that are not messy...like a bag of pretzels...no ice cream in line!).