A long time ago (2001), Jessica Bayliss and I wrote a paper about brain-computer interfaces.
I hadn't thought about it recently until I saw these videos showing two people using non-invasive brain interfaces to play pong and to type messages by just thinking.
2001 was a good year for me and brain interfaces. I presented a poster at the Perceptive User Interface (PUI) conference summarizing a paper co-authored with Martha, Christoph, and Curtis about using physiological feedback. That paper was about the emotion mouse (see a picture of it here), not brain interfaces, but the keynote by Melody Moore was about invasive (implanted) brain interfaces.