Joan got a much-needed night out on the town when Marley Shelton stopped by as Joan's old friend Kate. Shelton has been acting in TV and movies since she was a teen, but we know her best for her work with director Robert Rodriguez, in 2005's "Sin City" and the "Grindhouse" zombie flick "Planet Terror."
The halls of Sterling Cooper & Partners have been filled with a lot of familiar faces lately. Here are more than 20 "Mad Men" guest stars we recognize from previous roles in TV and movies. — Dave Nemetz, Yahoo! TV