From SpaceWeather.com:

If all goes according to plan, space shuttle Atlantis will undock from the International Space Station (ISS) on Monday morning, Feb. 18th, at approximately 4:30 am EST. This is good news for sky watchers across North America who will be able to witness a rare double flyby on Monday evening. Atlantis and the ISS will appear as a tight pair of lights, as bright as Jupiter or Venus, gliding in tandem across the twilight sky–an unforgettable sight. Favored cities include Los Angeles, New Orleans, Dallas, Jackson (MS), Pensacola, Philadelphia, Reno, San Diego and others. Double flybys continue on Tuesday, Feb 19th, albeit not as tight because the shuttle will be moving away from the ISS as it prepares to land on Wednesday, Feb. 20th.