I finally recorded the screencast number 7. It shows how to create Smalltalk classes and tests using SUnit. It also demonstrates the use of class packages and categories as well as the TestRunner tool. It follows a TDD rythm and presents 2 methods from SUnit. Couldn't make it smaller so it is a bit over the last screencasts' length but I think it is still reasonable (around 8 minutes).
As usual, I'll stop here but you can enjoy them:
Download the English version here or see it on Google Video.
Download the Portuguese version here or see it on Google Video.