A couple of years ago I told my family that summer of 2012 I owned them - it didn't matter what activities they might be in or whether they were dating, we were going on an extended trip to explore the Western United States.
We took that trip in June - two parents, three teenagers, and a long-time friend who joined us in CA (she's on the right in the picture below). We flew to Denver and then rented a minivan for three weeks. A friend of mine is a videographer and he suggested sending a camera with us -he was sure it would make for great viewing. I don't know if you've seen the show "The Middle," but I think he had something like that in mind.
Anyway, through the years we've created hundreds of rules for our children. It's tough to follow the Ten Commandments in one's own life, let alone enforcing hundreds of rules in the lives of others. I'm guessing that over time some of the rules weren't even consistent with one another.
So we boiled everything down to one rule for our trip: "If you know something you are doing is annoying, stop." Why we didn't come up with this rule before, I'll never know. But we were able to have a relaxing, enjoyable three weeks while enforcing just one rule. "Do you know that you're annoying your sister? Then stop." Simple.

For those who are interested, we traveled nearly 5000 miles through 10 states and came in $54.69 under budget. We took more than 1000 pictures (kudos to my parents for sitting through them) and saw countless wild and domesticated animals. We attended a rodeo, went whitewater rafting, saw Mount Rushmore, Crazy Horse, Devil's Tower, Yellowstone, Sequoia, and Zion, explored San Francisco on Segways, visited Alcatraz at night, were VIPs at Universal Studios, and got to visit with friends and extended family along the way.
There were some less than pleasant moments, but I'm confident there would have been more of those moments had we spent three weeks at home. Besides, all we had to do was ask: "Do you know that what you're doing is annoying? Then stop." Sometimes one rule is enough.