Michael Ausiello at TVGuide.com has been playing with his calculator, or maybe it was an abacus. Anyway, Mike has used some oh-so-creative math to add two and two together to get a major revelation on a CBS sitcom. Okay, here's the scoop. Mr. Ausiello has gotten an exclusive casting tidbit from How I Met Your Mother.

Alicia Silverstone, star of Clueless on the big screen, Miss Match on the small, has been signed for a series of episodes, a mini-arc.