I suggest to create a page which link from activiti.org home page contains list of Activiti Sample Application (even a bpmn20.xml is fine) and Case Study, I think it will be very good reference for the community, users and customers of Activiti. After all, don't you think we all learn by example?
For example, Grails Activiti Plugin Sample App - Vacation Request at http://code.google.com/p/grails-activiti-plugin/wiki/VacationRequestSampleApplication
What do you think? Please vote to support this idea.