Whether it’s an overlooked gun or an unplugged metal detector, security breaches at U.S. airports still make daily headlines, reflecting the fact that improved airline security is a work in progress six months after Sept. 11. To get a sense of how security at America’s busiest airports measures up next to more vigilant international ones, MSNBC.com visited five key airports in five days. Traveling with a carry-on filled with perfectly legal items that experts told us should at least draw attention, we found out that when it comes to security, inconsistencies still abound. Full Story