I've been a member of Photobucket for a long time now and they recently featured a section of Seasonal graphics. Contributed by members, free to use. There's some beautiful stuff on there and I've saved a load of them to my own albums on PB.
I'm not sure you have to join to use the graphics.
“Our hearts grow tender with childhood memories and love of kindred, and we are better throughout the year for having, in spirit, become a child again at Christmastime.”