www.codecademy.com. This is a free site that tries to get more people to be script-literate. This is achieved through taking the individual through a series of well planned and interactive lessons, broken up into sections, to be consumed weekly for a few weeks.
The interactive nature makes it really easy to pick up and retain the information learnt, because the student actually types in code himself/herself. The badges and achievements system works really well to motivate the student to carry on an stick with the lessons. ;)
Having had some scripting background, I breezed through a good part of the foundation lessons (earning points and badges as I go along)
Update: 3 Aug 2012
There is a new course at Codecademy for the Python language. Check out my blog post.