10 / 21

Larisa Oleynik

Oleynik made magic back in the '90s as telekinetic teen Alex Mack on Nickelodeon's "The Secret World of Alex Mack," and later co-starred with Julia Stiles and Heath Ledger in the 1999 big-screen hit "10 Things I Hate About You." Now she's Ken Cosgrove's better half Cynthia, appearing at Ken's side during work functions and dinner parties. But if they only knew the powers she possesses…

Do You Recognize These 'Mad Men' Guest Stars?

Yahoo TV

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