If you haven't signed up for the Toys 'R Us birthday club, check it out here. They will send you a card with a $3 giftcard (or coupon) valid on any purchase $3 or more. Don't forget to enter each of your kids.
When you check out at the store, they usually give your child a crown and helium balloon as well. My kids love it and it makes them feel really special.
This year, my son used this coupon to buy two pez dispensers. Oy! One for himself and one for his sister...awwwww! It's such a nice way to let them buy their own things and learn about money. They've learned a lot about reading prices this way. So we got 3 toys; the two pez dispensers and a Thomas train. All for free!