When Doug Mack picked up a 1963 edition of Europe on Five Dollars a Day, he stumbled on an inspired idea: to boldly go where millions have gone before, relying only on the advice of a travel guide that's nearly a half century out-of-date. Add to the mix his mother's much- documented grand tour through Europe in the late 1960s, and the result is a funny and fascinating journey into a new (old) world, and a disarming look at the ways the classic tourist experience has changed- and has not-in the last generation.

After a whirlwind...