Article here;
http://www.ox.ac.uk/media/science_blog/brainboosting.html
Recent research in Oxford and elsewhere has shown that one type of brain stimulation in particular, called transcranial direct current stimulation or TDCS, can be used to improve language and maths abilities, memory, problem solving, attention, even movement.
Critically, this is not just helping to restore function in those with impaired abilities. TDCS can be used to enhance healthy people’s mental capacities. Indeed, most of the research so far has been carried out in healthy adults.
The article goes on to discuss the ethics of the technique.
Here looks like a good place.
http://brmlab.cz/project/brain_hacking/tdcs
I'm going to be experimenting with them at the london hackspace so anyone from london is interested, give me a shout,
That ones actually a bit dangerous. The current regulator is rated to go that low, so it's going to be unreliable. In this instance unreliable means brain lesions.