Emblazoned on a long, tall, concrete barrier in the midst of a rocky Middle Eastern landscape is this spray-painted message: "Mirror, mirror on the wall. When will this senseless object fall?"

It's one of more than 900 graffiti messages that have been spray-painted by Palestinians on the controversial wall that separates Israel and the West Bank.

The painters take orders through a Web site that lets customers get a message on the wall. For the equivalent of $40, a Palestinian will spray paint the message and send three digital photos of it.

Anything goes -- marriage proposals, jokes, notes to friends -- as long as it isn't extremist, hate-filled, or pornographic, said Faris Arouri, one of the founders of the site...

... Nieuwenhuis said he heard about the site through van Oel, a friend, and liked the idea right away.

"I thought it was a brilliant idea to have something beautiful written on an ugly wall," he told CNN...