The Placebo Problem and Clinical Trials
The September 2009 issue of Wired has a nifty little article on the impact of placebo effects on pharmaceutical clinical trials and pharma company decision making: "Real. Fake. Both Can Cure Depression." by Steve Silberman.
Addendum on 28th August: As you will see from the comments, this piece is available on Wired magazine's website. You can access it here