The article recommended http://www.geocaching.com/, a site that lists by zip code the coordinates for caches. It's a free website, however, you have to join in order to get the information. At first I was rather skeptical because we live in a small town and I had never heard of Ge0-Caching. But upon my first visit, I found over 400 different cache sites in my town alone! Of course I joined and now I am eager to take my family out on a new adventure! The nice thing is that the site actually rates each cache (1-5) so you know ahead of time if it will be appropriate for your little ones. And with all of the "toys" we have from fast food restaurants, we are sure to have enough trinkets to leave for others!!
I will report back after our first treasure hunt mission, but in the mean time, please feel free to share your adventures! I think this is a great new discovery. One that won't cost too much and will involve the entire family!!!