In this chapter different types of brain/neuronal–computer interfaces are discussed and considered. This is all done from a practical perspective with applications in mind, although some of the implications are also considered. In particular results from experiments are discussed in terms of their meaning and application possibilities. The article is written from the perspective of scientific experimentation opening up realistic possibilities to be faced in the future rather than giving conclusive comments on the technologies employed. Human implantation and the merger of biology and technology are important elements.