While my friends were flipping burgers, my first job back in high school was teaching children to program in Logo and Basic, and I thought I would start there. But Logo isn't really for children, as illustrated by this common plight of a typical 8 year old kid.
Logo has improved a bit, for instead of a simple "syntax error", this version actually helps you figure out what is really wrong in case you spell “right” as “rite”. But I used to have children struggle over misspellings that they thought were right.
Of course, if you teach them the shortcuts with the abbreviations, we have fewer syntax errors, but when the program is complete, what you are left with is something more similar to assembly programming.
I also thought about teaching interactive fiction or MUDs, but it didn't take me long to come up with a list of what I wanted.