Prayer.

A recent study conducted by the Duke University Medical Center on 700 patients, found that having people pray for heart bypass surgery patients had no effect on their recovery. Researchers emphasized their work does not address whether God exists or answers prayers made on another's behalf. This result seems to contradict a previous study by the same authors that reported "cardiac patients who received intercessory prayer in addition to coronary stenting appeared to have better clinical outcomes than those treated with standard stenting therapy alone"

http://science.slashdot.org/article.pl?sid=06/04/03/149244&from=rss