The first ten years went by and my passport expired with me having been nowhere beyond the borders of the U.S.; it was stamp-free and in pristine condition. How sad is that? During those ten years, we'd had two children and it wasn't until 2003 that we began to seriously consider traveling out of the U.S. again. My first trip using my renewed passport was in 2005 when we sailed on a Disney Cruise to the Western Caribbean. Even then we could have used a birth certificate / driver's license combination, but having the passport was easier to deal with. Our children got their passports then as well.
Laws and requirements have changed so much in recent years that it's best to consult the U.S. Department of State's Bureau of Consular Affairs before traveling to be sure that you know what you'll need for exiting and entering the U.S. If you don't have a passport already, you can obtain one in less than a month's time generally, but it's recommended that you do it 3-4 months in advance of your travel dates. Also it is currently required for entrance into some countries that your U.S. passport be valid for 6 months or more after your scheduled date of return.
Passports for youth are valid for half the time as adult passports, so we've had to renew our sons' passports already. At least they had used theirs unlike my first one. We have learned that when traveling via cruise ship, it's not often that you'll get a stamp in your passport, but you can find government officials at various port terminals who are willing to inspect your documents and stamp your passport. For some ports, you are required to go through Immigration at the port before leaving the cruise ship area or have your passport inspected upon return. We found this to be the case in both St. Petersburg, Russia, and Stockholm, Sweden when we cruised in the Baltic in 2010. In 2011, our Alaskan cruise left from Vancouver, so we collected stamps pre-sailing there.
For our trip this summer, we have not found that our passports will be inspected except upon arrival and departure in Barcelona. However, we've learned that we can look for a stamper while in Monte Carlo to add the Principality of Monaco to our passport stamp collection.