StephenH is right. Richardson Bike Mart had a tandem hanging on a rack next to the Trek Mountaintrains when I was there at Thanksgiving. It was used, IIRC - a rental item, but in good shape. First time I had ever seen one.
Oh, and I sent them a note about being sold the wrong pedals, and they are sending me out the correct set at no charge (no need to return the first set). Nice.... I'd deal with them again.