Starting next month, patrons of some Phoenix-area businesses won't be able to escape advertising even in the rest-rooms.

The walls of stalls can be used to promote everything from pantyhose to taxis, says 26-year-old entrepreneur Jeff Rons, the creator of bathroom advertising.His company, In-Stall Ad Systems, has lined up space in the restrooms of the Celebrity Theater, Top Shelf Restaurants, McDuffy's Sports Bar, an office building and three tour-bus companies, he said.

Businesses install up to 10 framed, 6-by-6-inch ads on the back of each stall door, and the advertiser cost is about $180 per month for a five-stall display guaranteed to reach consumers out of sight of television or print.

"Everyone reads in the bathroom," he said.