Came across this one today
CS101 teaches the essential ideas of Computer Science for a zero-prior-experience audience. Computers can appear very complicated, but in reality, computers work within just a few, simple patterns. CS101 demystifies and brings those patterns to life, which is useful for anyone using computers today.
In CS101, students play and experiment with short bits of "computer code" to bring to life to the power and limitations of computers. Everything works within the browser, so there is no extra software to download or install. CS101 also provides a general background on computers today: what is a computer, what is hardware, what is software, what is the internet. No previous experience is required other than the ability to use a web browser.
Course is available at http://www.cs101-class.org/
Wondering if it may be something to get my year 13 students involved with, though I need a bit more a guideline on what is to be taught each week, so I can prepare my lessons and check the content to suit