Mexico's sprawling capital: Mexico City, is making headlines as the newest urban playground for hip globe-trotters. Its trendy (and affordable) restaurants, freewheeling nightlife, and outstanding museums are just a few of the things responsible for this buzz. Nowhere is the transformation more obvious than around the central square, where long-neglected streets have been repaved with cobblestones and lined with trees. Now people even stroll here at night -- unheard of a few years ago. Some people are daunted by the city's size, but the clean, speedy subway system makes it easy to get to even the most distant neighborhoods. But what about the old problems, like the crime? A little better, but you still need to keep your wits about you. Traffic? About the same. Smog? Dramatically better. This Mexico City is a breath of fresh air.