Best intended for long, multi-state trips, make a list of the 50 states for each participating member in the car, and they each check off the state when they see a car with that state's license plate.

This can be entertaining for kids as well as adults and it can also be cooperative or competitive. An added challenge is not allowing checkoffs for the state you're currently in. The game exercises one's observational skills as well as teaching what each state's license plate design looks like and can also be played simultaneously while conversing or listening to music, allowing it to last for hours.

For a twist, create individual BINGO cards for each player with various states listed.

The usefulness of a Swiss army knife or other similar utility tool can not be understated.

Beyond the obvious uses of the available tools like the can and bottle openers and the knife and scissors to open packaging, there are also several other potential uses:

• The point of the knife is an effective screwdriver for very small screws like those seen on the battery doors of many electronic devices (fresh batteries also being an essential item to pack).
• The scissors are strong enough to cut the binding of a spiral notebook if it comes undone.

Just be sure not to store it in your carry-on luggage -- the TSA will confiscate your precious tool!