Please I beg you bring a camera or two and plenty of film/digital memory cards, you will be so disappointed if you can't record the magnificent Grand Canyon on a few photographs.
It is worth taking to many photos here, because it isn't worth the risk of not having a great photo to show your kids/grand kids.
Luggage and bags:
If you're planning to hike, I'm sure you already know what to carry! ;) Basic stuff... a good backpack, LOTS OF WATER (remember Nalgene bottles), skittles (these can provide a good sugar rush)... you know the drill.
Clothing/Shoes/Weather Gear: Well, bring shorts and long pants... the days will be really hot, especially inside the canyon. But on the other hand... at night it can be cool and if rain is passing through, the inner canyon can be cool too. Pack accordingly. Winter can see snow!
Toiletries and Medical Supplies: If you're hiking, bring some aspirin. It's a good thing to have if you start having a heart attack while hiking. It'll definitely help.
Photo Equipment: Brings lot of film. Unfortunately, you can't do the canyon justice by taking pictures. It's very difficult to capture its majesty. Yet, bring film because you'll want to still take tons of pictures! Bring a tripod if you think you'll seriously take some really nice shots.
Luggage and bags:
You can travel light coming to Grand Canyon because most items are provided for you in the General Store. I recommend you, however, that you bring the following necessities: appropriate footwear, sturdy shoes (Salomon are good ones!)! Alarm-clock to wake-up in the morning at 4, 5 or 6 to see the sunset: Yes, I know is soon but is an INCREDIBLE EXPERIENCE !!!! Personal toiletries, clothes hangers, hiking and camping gear.
Clothing/Shoes/Weather Gear: With Grand Canyon as your destination, you will find unlimited amounts of outdoor activity and recreation. There are 840 kilometers of hiking trails in the park alone, as well as camping, athletics, mountain climbing and more!!!!! Grand Canyon National Park is surrounded by open public lands for outstanding recreation, you need a good pair of shoes!!! Clothes fresh by day and a jacket by night sometimes is cold in summer.
Photo Equipment: No problems to find coils. Maybe Grand Canyon is the best business for Kodak and specially with japanese people (How the hell can pay this amount of pictures????!!!)
Photo Equipment: Bring your camera and extra film. I took so many pictures because everywhere I looked I saw something more beautiful than one minute earlier. The second time I went I took a roll of black and white film too and I thought that the pictures turned out really awesome!