Every year there is an event called eNTERFACE. It is announced as a summer workshop, but it is a bit more. About teams work on different multimodal human-computer interaction projects for 4 weeks, and there are some tutorials and lectures. You can submit a project proposal yourself if you like, or you can join the team for the project of somebody else.
Last year Christian Muehl from our group was team leader for a project which resulted in the game Bacteria Hunt, in which you play an amoeba controlled by keyboard, SSVEP, and alpha activity. The goal is to eat as many bacteria as you can.