Interesting New York Times article about the International House of Prayer --
The well-populated prayer room and the devout community growing up around it are at the epicenter of a little known but expanding national network: dozens of groups that are stressing perpetual prayer in a way seldom seen in modern America, said Marcus Yoars, the editor of Charisma, an evangelical magazine. Many of them were inspired by the operation here, though none have maintained such an elaborate 24-hour system of worship, seen around the world on a live webcast.
They've been doing that perpetual prayer thing for a long, long time in ... Mecca!