To simplify the process, create an Animoto folder in your pictures. Copy and paste all of the images you wish to include in your greeting card to the folder so that when you are asked to upload your images, you can choose all of the photos at once (Control + shift).
I originally uploaded 18 pictures to my working file in Animoto, but only 9 of them were incorporated into the free 30 second greeting card. Using the remix feature, I was able to delete 5 of the pictures, rearrange the order of the remaining ones, and choose another tune which allowed all 13 images to be used.
Animoto simplifies posting your videos to many sites, including Facebook, WordPress, MySpace, and more.