My son was excited to help me hang hooks in his room to hang up his hats. I can add more hooks to the wall, and then remove them with no wall damage when he gets older.
3M hooks are sold many places, including hardware stores like Home Depot and discount department stores like Target. When purchasing 3M hooks, I have found it is good to estimate the hanging item's weight and purchase hooks that hold twice that weight. For example, buy 5-pound hooks to hold 2 and a half pounds.