To start with: I am a Disney fan -- to be precise, it's a lot like the way Jack Nicholson is a Laker fan -- so on my very nearly annual expeditions to a Disney park, I don't really need the map. I have memorized shortcuts and low-traffic restrooms, how to get all the good stuff done in one day, and loads more random bits (look closely in the Hall Of Presidents; molds for their faces are used on other animatronics around the park), mostly because carrying them around in my head was the easiest way to carry them.
Then I got my iPhone (my first smartphone) and was able to put data on my phone (which I always carry with me). Enter the Walt Disney World Notescast. This $0.99 app is a handy planning/informational tool that can guide your entire Walt Disney World trip, from vacation packages to tips on annual events and park history. I tested the iPhone version of this app, but TimeStream Software also sells a $1.99 version for notes-capable classic iPods and nanos. It doesn't rely on a data connection and you can carry all this info with you easily.
When you first launch the application, you get a list of options to choose from. I liked the variety of options, but I wish I could customize or at least re-order it so I could get at a few of the options more quickly. There is a bookmark system available, but I ended up bookmarking a lot of things so that list went non-functional pretty quickly. And while I understand not having a ton of information on one page, I had a hard time figuring out why there were breaks between, for example, "Tours of EPCOT I" and "Tours of EPCOT II". I love the list of phone numbers, especially since I can tap the number to make the call. In the now cutthroat world of Disney Dining, having that number handy -- as well as the ticket line and even the camping and Magical Express numbers, not usually easy to find on the WDW site -- is a huge convenience.