Flying Blue...Go Blue

My US visa is finally approved and I got 5 yrs...leaving for Michigan in 2 weeks time with Air France...joined Flying Blue membership...So many airlines come up with various mileage program...I think it's time to design a card that can store various membership data so that we don't have to carry so many cards around. I think going to michigan will be like going back home.
It's funny because last time, I was always going home to asia from Michigan...And now, the comparison is between Germany and Michigan..So, it's more homely in Michigan than in Hannover. What should I do in Michigan? shopping I guess...