Wiki Christmas

Everybody in my family makes Christmas lists and then people buy things on those lists, but nobody who wants to buy things knows what the others are bought so far. For a procrastinator like me, this is an undesirable situation because I don't want to waste time bringing things back to the store in case somebody else has already bought it.

There ought to be some sort of website where people can go to make a Christmas list and then others can view it and if they purchase something on the list, they can flag that gift idea. The person who made the list wouldn't know, but any other people viewing the list would be able to see that that gift was taken already.

I hope that this is already invented somewhere in the vast reaches of the internet, and if it isn't, maybe I'll get around to it sometime.

UPDATE: There is such a tool!