Wired has a two part story on neuro engineering using light and magnetic fields (in that order for the two parts) at:
http://www.wired.com/science/discoveries/news/2009/03/neuroengineering1 and http://www.wired.com/science/discoveries/news/2009/03/neuroengineering2
Part two also contains a link to an open source TMS machine which looks like it could be a lot of fun (http://transcenmentalism.org/OpenStim/tiki-index.php).
