If you look up the respective Polish cities on wikipedia.org there should be a list at the bottom of the page of their sister cities around the globe. Cheers!
Does Krakow have an annual public "Hash Bash" where people smoke their brains out (pun intended) every year in the parks and on the streets ?
There is a reason why Ann Arbor is called A squared or arrogant asses. Krakow is has much higher standards then A.A. Michigan pompous over educated idiots.