Computer science books for kids

Avril really likes Computational Fairy Tales and this reminded me of other books that may be of interest although I haven't seen them myself yet:

• Lauren Ipsum
• Best Practices of Spell Design
• Hello Ruby.

Do you know any other good books that teach kids programming?

Update: I just saw this post with more interesting books: Teach kids programming (A collection of resources).

Bootstrap

I was looking for new programming projects for Avril because Scratch was a bit too limiting and I found Bootstrap. It's a very interesting program that teaches algebra and computer programming at the same time. Today we finished Unit 1. I will try to modify the rest of the program to make it appropriate to an 8 year-old but I'm encouraged by the fact that the goal of the Bootstrap program is to develop a video game like the NinjaCat example they provide and Avril and I have already developed a very similar game in Scratch: Run, Scratchy, Run!
The new game will be about a mermaid dog fighting a shark: