One of my kids favorite presents is "Family Bucks" to spend at the after-Christmas sales. (I make up phoney money on the computer and personalize them with our name). This keeps me from having to give them real money, and I can pay for their selections with mine instead of doing a separate transaction.
An added benefit is that it puts a limit on how much they ask us to buy for them. Each item is carefully considered when it is coming from their own pocket!