DIY FTW. There was a DIY MRI project I remember reading about, I’ll try and find the link.
Many people are interested in what is called neurofeedback or EEG biofeedback training, a generic mental training method which makes the trainee consciously aware of the general activity in the brain. This method shows great potential for improving many mental capabilities and exploring consciousness. Other people want to do experiments with brain-computer interfaces or just want to have a look at their brain at work.
Unfortunately, commercial EEG devices are generally too expensive to become a hobbyist tool or toy.
The OpenEEG project is about making plans and software for do-it-yourself EEG devices available for free (as in GPL). It is aimed toward amateurs who would like to experiment with EEG. However, if you are a pro in any of the fields of electronics, neurofeedback, software development etc., you are of course welcome to join the mailing-list and share your wisdom.
Right now, this site is mostly about the hardware; schematics, part lists, building instructions etc. However, a few members have developed some useful software which is hosted on their own websites. You can find these through the software pages.