Hardware traditionally used for capturing brain activity, especially EEG - which is most popular BCI technique for today - is very cumbersome. BCI systems based on such hardware may satisfy the disabled, but if we want to be successfull in entertaiment & games industry, those devices are unacceptable.
Because of this a lot of companies like NeuroSky developed "head-ready" devices that can be just weared-on and played-with, but these devices cannot yet compete with traditional systems for EEG recording: they usually rely only on a very few forehead sensors, which mean brain signals registered by these devices are very artifacted and do not provide as much info as signals captured from the whole head would.
I found one interesting device which is a "head-ready" helmet with sensors located on head area, and researches who developed it successfully used it to navigate a car. You can watch demo on YouTube:
We have a new member in our group Aureli Soria-Frisch who works in Starlab. They developed a dry, wireless EEG system Enobio. It also employs only forehead sensors, but looks much more professional than similar products.
(this is not an advertisiment - I want to collect info about good BCI hardware in this topic!)