Upon checking into the Sheraton Denver downtown, the clerk gave me two unfamiliar looking magnetic stripe room key cards. You know, the plastic ones that are rapidly filling up garbage dumps. "They’re wood, but they don’t work too well in our doors," she said a bit sheepishly, handing me the usual slick credit card plastic set. "So here are your other keys." Valiant effort at replacing the plastic room keys, I said. Too bad it didn’t work.