Scratch's url is http://www.scratch.mit.edu/
I have written two simple programs in accessing and learning how to use it:
counting from scratch rd-v1
Cat and ghost on moon RD-v1
I am going to start developing a screencast on using Scratch ... and the basics of programming for interactive discussion here in Playground 2.0. The Scratch site itself has a lot of excellent help for getting started ... and once you are registered and logged in, you can download te programs to examine how they were constructed.