When we were at Epcot last week we took advantage of the Meet and Greet for Disney Visa Cardholders. This is available from 1:30-4:30pm daily at Innovations West. You will need to show your Disney Visa Card so be sure to carry it with you.
Be sure to bring your autograph books or autograph mat with you since you will be able to get a couple autographs.I hear it is typically Mickey and someone else but there is no guarantee who it will be and how many characters there are.
You will also be able to get a free 5×7 print of your group. When you are at the meet and greet they will take some pictures and add it to your photopass card. At least an hour later you can take your photopass card down to the photo store. It is right next to the entrance of Spaceship Earth. On the right if you are facing the ride. You will be able to pick a border and they will print the picture for you. You can wait until the end of the day but it is more likely to be crowded at that point.
Here is our family picture.