I know that when I was a kid it was family that got me interested in the outdoors. Lots and lots of camping trips, relatively short hikes, and trips with the grandparents in their RV. That last one was probably the most fun of them all, combining grandparents with a weekend getaway and plenty of sugary snacks and s'mores.
It was always a blast to be able to explore new areas, sleep in, smell the breakfast cooking in the morning, stay up late with a flashlight, get sunburned at the beach, build new engineering marvels in the sand, look for shooting stars, help hold the hose at the RV dump station in 100+ degree temperatures (phew), etc...
Then there were always the bloodthirsty animals outside the tent if I was sleeping outside... in reality they were probably raccoons or squirrels. <img src="/images/graemlins/grin.gif" alt="" />
I guess overall I'd say it wasn't just having a destination, but the journey getting there and back was just as much fun. Geez, that sounds cliche, but it's the truth.
(P.S. - that combination whistle thing looks like junk. I'll echo the others and say just buy a Fox 40 whistle.)