Rough week for celebrity spokespeople

By now everyone has heard that America's golden boy, Michael Phelps, has tarnished his image by getting photographed with a bong. The misstep proved costly as Kellogg's dropped the swimmer from future endorsements.

But Phelps isn't alone. Wrigley's jumped off the Chris Brown bandwagon after the singer's recent arrest for domestic violence. "Got Milk" quickly followed suit and pulled their ads featuring the singer.

And what do you suppose will happen now that Alex Rodriguez has admitted to using steroids? He's estimated to earn millions through contracts with the likes of Nike, Pepsi, and Guitar Hero (also staring Phelps). But do these companies want to associate themselves with a cheater?

Advertising history is plagued with bad memories of the celebrity endorsement gone wrong – need we remind you of the O.J. Simpson and Hertz partnership? Are celebrity endorsements really worth the risk? What do you think?