Here are a few gift ideas for 5, 6, or 7 year old.
1. A bigger bike. Kids learn to ride a bike at 3 or 4 and tend to out grow it by the time they are five or six. Hook him up with a new ride. Often times used bikes are very inexpensive on craigslist. Look for something with a 16 inch wheelbase.
2. This is the age that boys take interests in sports. Baseball mit, bat, and balls make a great gift. Hockey stick if he's Canadian, and soccer ball if they come from just about any other part of the world.
3. A puppy. Better clear it with the parents first, but this is an age where kids can feed a dog and do a little work. Give the kid a dose of responsibility. (Note: Please don't give our kids pets).
4. Books. My favorite book is Where the Red Fern Grows. Buy it, sign it, and then read it to him. Boys love this book. Then follow it up by watching the movie with popcorn and candy.
5. Weapons. Boys at this age tend to turn just about anything into a weapon. Nerf guns, soft spears, perhaps blow darts will surely be enjoyed by most boys. Be prepared. They will most likely shoot you, eachother, pets and cars. Trust me. (Note: Have to know the parents for this one. Many don't like anything to do with guns and violence, but when I was a kid, I loved this stuff).