With the help of the audience, I'll try to create a complex webapp within 30 minutes. Complex in the sense of: Custom use case (unprepared, told by audience), custom JSON/REST backend, beautiful HTML5/CSS3 template, dynamic data, user interaction, Twitter/FB connect). Everything we need is the Open Source framework Structr, on top of the graph database Neo4j. This will be very interactive, and even fun if it works. ;-)