Sorry for borrowing the old movie title. A couple of things on the secure side would be to use the Qwest business center on Concourse B if you brought your laptop. The prices aren't as outrageous as the kiosks you'll find on the main level of the terminals. The business center is on the upper level in the center of Concourse B and usually pretty quiet most days and good for making phone calls to re-book flights if necessary. My favorite restaurants at DEN are Pour la France (Concourse B) and Chef Jimmy's (Concourse A). Chef Jimmy's has a decent bar that usually has spaces open when the small restaurant area is full. The www.cowboy.bar has made the notable circuits (Forbes and some others) for being an actual bar in an airport. The Mesa Verde restaurant is the smoking lounge on Concourse A that just opened but is supposed to be not as smoky as the lounge in B. BA, CO and UA have business lounges if you qualify for those things. Note, the Concourses are connected by an underground train in the center of each.