According to CBC Canada, a new over-the-counter diet pill is now available in the US:

An over-the-counter diet pill approved by the U.S. Food and Drug Administration hits store shelves Friday, but some doctors are questioning if its benefits are worth its costs.

The over-the-counter drug orlistat, sold in the U.S. as Alli, comes in 60 milligram pills, half that of the prescription version, which has been available in Canada for a few years.

Hang on to your cheering. The news isn't all good. Several things, including bad side effects and a high cost, could make the pill far less desirable.
The Diet Blog reports:

When taken with meals, orlistat blocks the absorption of about one-quarter of any fat consumed. That fat - the equivalent of about 150 to 200 calories - is passed out of the body in stools, which can be loose or oily as a result. Other side effects include gas, incontinence and oily spotting. About half of patients in trials experienced such side effects, the company said.

The diet pill has just been approved, and already there's a diet book out about it - the alli Diet Plan, by Caroline Apovian M.D. She is the Associate Professor of Medicine at the boston university School of Medicine; Director of the Center for Nutrition and Weight Management and Co-director of the Nutrition Support Service at Boston Medical Center. She is also Director of Clinical Research for the Obesity Research Center at Boston Medical Center.