Hi
Students working in my group developed some cool packages last semester. I will post one per thread so people can comment.
They are all listed in http://www.weg.ee.usyd.edu.au/projects/sc_ug2002
You can access the code, a power point presentation with a video of them summarizing the project, and the full thesis.
For the curious: the projects took about 200 hours of effort for people with no previous experience in openACS.
I will try to perform some more QA later in the year, meanwhile enjoy.
The IMAP webmail client was developed by Ayman Mohamed.
He used PosgreSQL, but I think it is mostly database independent, except maybe for the addressbook.