Over at Wired, Melinda Wenner writes about transcranial magnetic stimulation where with a few Transcranial Zaps they can possibly treat migraines, depression, help you sleep better and even make you smarter.
Inducing brain activity may be a good idea in some cases such as brain disorders as exemplified by the coma patient that recently responded to a Brain Pacemaker. At the same time I think we have to be wary of the fact that the brain is trainable.
I worry the each time you use this device that you are inadvertently re-enforcing some random or not so random set of pathways with unknown consequences. Beyond this, TMS is considered safe ( relative to electroconvulsive therapy ! ) and there is a slight risk of siezures.
I think for now I will wait for a few others to become guinea pigs before I exchange it for counting sheep.