Laws on smoking in public vary from state to state. In Iowa, they are very strict: at a rest stop along the highway you can only smoke if you are inside your car with the windows closed.
A highlight of the trip was an delicious Iowa version of Chinese hot pot. (Our friends spent a month in China this winter, visiting their daughter who is teaching there.)
Pappajohn Sculpture Park. It's a gorgeous open space right downtown and is full of large sculptures by well known artists. One of the most popular works seems to be Nomad by Jaume Plensa. It's fun to walk inside the figure and look at the sky. (Plensa is also responsible for the wonderful fountain in Chicago's Millenium Park.)