One thing to keep in mind when considering a trip out of the country is the wait time for passport books. The application process is not especially difficult, but there can be a significant backlog of applications at the official passport office. Sometimes a passport application can be expedited, but that still only brings the potential wait time to weeks instead of months.
There are still some countries that will allow tourists to enter with documents other than a passport, but most major destinations will require the presentation of a valid passport. It's one thing to plan a trip to Europe at the end of the year, because the passport application will most likely be processed by that time. Some people may win a trip in a contest or be invited to an overseas wedding, however, and have far less time to wait on a valid passport.