Hey Carlos,
Had a chance to listen to this podcast - good job.

Here are my extra little tidbits:
Magic Kingdom - You mentioned the paintbrush on Tom Sawyer's Island. My girls found this in Sept 2005. It was 4:30 in the afternoon and we just walked upon it. I knew what it was and had the girls bring it back to the boat. The "prize" was a certificate that served as a "fastpass" for either Thunder Run or Splash Mountain. We kept it as a souvenir instead. Incidentally, they were the first ones to find it that day (at 4:30 p.m.) so you never know. ...fastpasses were still relatively new for the general public. Hopefully, they give a better prize now!
Also, there was a pirate academy last time that my daughter volunteered for. All kids who particpated in the show received:

We just stumbled upon the show. Always take the time to enjoy these "live shows" as they are what makes Disney parks more special ... don't just focus on ride to ride.
Animation Drawings - To add to what Chantal was saying. The first time we did this, I carefully carried all our drawings in a roll for the rest of the day. Since then I have learned to simply take a digital pic of each drawing while at the studio.
Epcot - There are a lot of hidden gems in Futureworld. There are the free souvenir e-mail pics you can get at the end of the Spaceship Earth ride. Just fill out your e-mail on the computers at the end and they will be sent home. At the end of the Figment ride, Kodak has kiosks that you can take your picture, and place it on an animal or flower, or add accessories to it. These can be e-mailed home as well.
Here are a few:
From 2005


From 2009:


Also, Innoventions can be a hidden gem. My girls have made there own paper (great souvenirs), and have participated in many shows throughout the years. Generally, they get a sticker for being in the show.
Also, don't forget the new Kim Possible activity if it's still there. Definitely a great, interactive way for kids to visit World Showcase.
I think Epcot in general is a hidden gem - many families with young children skip that park but my girls love it!