The man who coined the phrase "a penny saved is a penny earned" lived and died by the mantra. In his will, he left the cities of Boston and Philadelphia each 1,000 pounds sterling (worth about $4,500 at the time), with the caveat that they could not touch it for 200 years. Both followed his wishes and, in 1990, found that those few thousands were worth millions. And for more money secrets, see the 20 Crazy Facts You Never Knew About One Dollar Bills.