A five or six year old can handle a backpacking trip just fine, as long as you making the hiking part fun. So, short hikes with plenty of creeks, ponds, wild horses, etc., are good. Long slogs through the "green tunnel" to a single view of some distant peaks -- not so good.

A kid that age should have *very little* on his or her back. A rain shell, some gorp, a full water bottle, maybe a fleece jacket. My daughter also carried a small stuffed animal, Beanie Baby size. A flashlight or headlamp is a really good idea. Teach him or her what to do if separated from the group. (Hug a tree. Stay in one place. Don't hide from rescuers.) While on the trail, talk, make up stoies, sing, etc.

Don't skimp on clothing -- the kid will need synthetic hiking clothes (not cotton), real rain gear, and fleece for around camp and on breaks. There is nothing worse than a cold wet kid after a summer thunderstorm in a "water resistant" jacket. (Ask me how I know this.... <img src="/forums/images/graemlins/shocked.gif" alt="" />) As for footwear, light sneakers are fine, but again, use synthetic or wool socks, not cotton. A good wide-brimmed hat is nice, but a ball cap will do.

Yes, the parent will need to carry everything else -- 2 sleeping bags, larger tent, more food, emergency supplies, books, etc. I had about 65 pounds on my back the first time we took our 5-year old to the Mt Rogers high country for a long weekend hike. (OK, that was before we "saw the light," as it were, but still.)

Go slow, stop a lot, have fun, enjoy the outdoors. Don't set unrealistic mileage goals. Once your kid is 8 or 9, you'll have a hard time keeping up on the trail.