Foraging for a glazed doughnut at 2 a.m. can bring unusual rewards. Stumble into this strip-mall joint and you'll find flat-screen computers, a couch, a leather recliner, and conference rooms for rent. But the most unexpected luxury appears in the women's rest­room, where, attached to the ordinary toilet seat, is... a bidet. For the uninitiated, bidets are a French invention designed to wash the areas that Americans generally clean with toilet paper. But according to Dunkin' Donuts manager Emad, they are common in the Middle East, specifically his native Palestine. He was thrilled when the owner of the shop, who is Muslim, installed a portable bidet in the restroom. Emad says the bidet complies with his religious ideals of cleanliness. "We always use these," Emad says. "It's a good idea. While you sit down, just clean up."