The campus is very beautiful year round. I personally like spring the best (and early summer), because the lilac trees and flowers are blossoming & blooming all around, and it smells heavenly (if you are smelling the flowers that is..hehe). There are a lot of trees all around campus that provide excellent scenery. Central Campus is especially beautiful. It's like a large park. Iowa State's Central Campus has been named one of the 3 most beautiful Central Campuses. There's a giant plaque in front of Curtiss Hall all about it or you can learn more about it on the ISU homepage. :-) I know Ames isn't really on the way anywhere (unless you're traveling Hwy 35 perhaps), but if you ever end up in central Iowa, it wouldn't be the worst waste of time. There are other things to do too, no worries. ;-)
West Street and Wilmoth Block Party
It's hard to catch... the date changes yearly depending on who gets off their lazy ass to apply for a permit... but it's worth hanging around to catch a street full of hippies in all of their dirty, drunken glory.