Sienna Miller
In 2006, Sienna Miller met up with a special Santa to unveil the Fifth Avenue Cartier Maison's traditional holiday decor. The world's most famous St. Nick doppelganger, known as Santa to the Stars, has worked with the famed jeweler for more than 20 years, bringing holiday cheer to such visiting luminaries as Madonna, Rachel Weisz and Uma Thurman. Part of what sets this Santa apart is his bling: a double-C logo belt, a signature watch and round-framed specs, all from the Cartier line.