Europe June 2010 Western Europe short stay tour: Barcelona one week, then Paris, Rome, and Berlin in 5 days!

Just realized that I will be flying to so many different places: Western Europe 11-23 June, then hop on a plane back home to the US and fly one day later to Washington DC to stay for three days. Then, I get to go to Chicago for a week. Si todo sale bien, I return home on the 1st of July. I wonder how I'll feel after so many hours spent on airplanes!