Information on TMS for depression: From Dr. Max Fink's book Electroconvulsive therapy: A guide for professionals and their patients (Oxford University Press, 2009, pp, 112-113):

Transcranial Magnetic Stimulation (TMS)

A recently introduced technology applies repetitive magnetic pulses to the head without inducing a seizure. Anesthesia is not needed.. The details of the stimulation currents, number and requency of pulses, and stimulating paddle location are under continuing study. The variations in placement of the stimulating paddle and the number and frequency of stimulations, are many, but as of mid-2008, no study had shown sustained benefit for any variation of TMS in a psychiatric illness.

In one study, deprssed patients were treated with a 15-day course of daily TS stimulation to the left dorsolateral prefrontal cortex. Of the patients who received either TMS or ECT, 59% of those treated with ECT achieved remission compared to 17% of those treated with TMS....

In another large multisite study of daily real TMS and sham TMS over six weeks (30 sessions), a 50% reduction in mood scores was recorded in 18% and 34% of real-treated patients at weeks 4 and 6, respectively, compared to 11% and 12% of sham-treated patients. ..."

Dr. Fink further states:
Transcranial magnetic stimulation is not approved for clinical use in the United States but is widely used experimentally."

and

"An accidental seizure is a hazard of TMS."

U.S. News and World Report recently ran a series of articles on brain stimulation:
Check out the following recent articles:

http://health.usnews.com/articles/health/brain-and-behavior/2009/07/15/brain-stimulation-electroconvulsive-therapy.html

http://health.usnews.com/articles/health/brain-and-behavior/2009/07/15/brain-stimulation-transcranial-magnetic-stimulation.html

http://health.usnews.com/articles/health/brain-and-behavior/2009/07/15/deep-brain-stimulation-a-pacemaker-for-parkinsons-disease-and-more.html?loomia_ow=t0:s0:a41:g2:r5:c0.049801:b264 44880:z0&s_cid=loomia:brain-stimulation-transcranial-magnetic-stimulation

http://health.usnews.com/articles/health/brain-and-behavior/2009/06/30/mark-george-treating-depression-with-an-electromagnet.html?loomia_ow=t0:s0:a41:g2:r2:c0.06 6369:b26444718:z0&s_cid=loomia:deep-brain-stimulation-a-pacemaker-for-parkinsons-disease-and-more