Sadly, I didn't have the time to go to the congress, but I've seen their club in Munich. Their spare-time projects impressed me quite a bit: the members unlock

Sadly, I didn't have the time to go to the congress, but I've seen their club in Munich. Their spare-time projects impressed me quite a bit: the members unlock the door with a digital key sent to the lock via wlan; they built that 3D-printer that can print it's own components, they have a self-written mandelbrot-based music visualizer, a soda machine where you can pay with a specially prepared USB-stick (anonymously, of course), computer-controlled lights in the whole flat, and lots of other cool stuff. The members were very nice people, too.