This year my son raised money for the Yarloop fire victims instead of presents. He turned 5 and had 15 kids at his party. Honestly I did it because I didn't want 15 presents coming into the house that I knew he probably wouldn't play with.
He raised $250 and donated it through his school. He was so happy with this.
If people genuinely are troubled by the amount of stuff their kids get I'd strongly recommend doing this.