Many thanks to a correspondent who has observed that the Royal Mail have made available the Christmas stamps from 2007 which have an image of the Our Lady with the child Jesus. There are designs for first and second class stamps. Go to the Stamp Sheets page in the online shop and scroll to the foot of the page.
I think that this is a very good idea. Nowadays, a company like the Royal Mail can offer "print on demand" via the internet and people can vote with their plastic for the stamps that they would like to use to send Christmas cards. (The 2008 stamps feature pantomime characters.)
There is another interesting feature that I have not seen before. You can now make up your own custom stamps with a feature called "Smilers" They are a bit pricey but would be quite fun to do. Here is an example I made as a preview: