It's the talk of Georgetown: What's Mark Penn, Sen. Hillary Clinton's chief strategist and pollster, doing building a tunnel between his two houses on O Street nw? Among the suspicions: It's a hideout for Clinton should she become president and face a terrorist attack. Or it's a lazy man's way to avoid walking across the small lot without going outside. Actually, Penn tells us, "Really, all it is is that the two houses are just being connected and then everything is going to be put back." He says it took months to win building permits to let him rip out the one-story raised yard, build the tunnel area, and redo the patio space between the two houses, assessed at over $7 million. As for the lazy-man crack, the extraordinarily busy chairman of Burson-Marsteller public relations and head of Penn, Schoen & Berland market research says he's planning to turn the tunnel area into an exercise room. Interestingly, he wasn't the first owner with tunnel vision. He discovered that the previous owner had plans to do the same thing.