What if there was a communal Christmas Tree in Britannia where we could leave gift boxes to other players.The gift boxes will be submitted through a drop box, and then displayed around the tree. At a certain date, they would be distributed. Maybe just even a book saying "A has a gift for B".
Distribution could be through the address book system, but it really needs a trusted person to act as escrow.
A thread on this forum could fill in what we can't do ingame - such as undelivered gifts or thanks for the chunk of coal

It's an idea that is ripe for abuse, but most players I hope will get into the spirit.
I invite discussion. This could be Staff administered or a trusted player being Santa!