Change your working copy to a different repository
In the context of the cafe iterations, you might like to check out the next iteration in the same working directory rather than having to blow away the files and check out the next step.
SVN Switch
Example: Updating your working copy from Iteration 1 to Iteration 2
Command-line approach
Make sure you're in the root directory working directory (/opt/cafe-2.2/ if you followed the Development Environment Setup Walkthrough)
svn switch https://source.sakaiproject.org/contrib/programmerscafe/tags/sakai-2.2/tasklist-iteration2
Windows approach (assumes TortoiseSVN)
Right-click the /opt/cafe2.2 directory (assuming you're using the suggested working copy directory)
TortoiseSVN -> Switch...
Change the "To URL" to https://source.sakaiproject.org/contrib/programmerscafe/tags/sakai-2.2/tasklist-iteration2 and click "OK"