This summer, tens of millions of American parents will brave the age-old hazards of traveling with children: roadside diaper changes, backseat imbroglios, teenagers who would rather be anywhere else--especially since the dog just had an accident behind the cooler. According to Meredith Corp.'s Family Vacation Travel Report, about 20% of traveling parents will borrow even more trouble by including grandparents in the family vacation, while others will join the growing trend of squeezing extra mileage out of business trips by bringing the kids along. Says a road-weary mom: "Sometimes it takes so much effort to get where we're going that it's...

