Jon Hamm lends his voice to The Simpsons for that show's 12/12/10 episode. He portrays a FBI agent who clashes with Homer.
Added:
Martha Stewart appears as herself on the 12/5/10 episode of The Simpsons. This is a shot of the homemaker in that familiar role.
Added:
Danica Patrick and Rachel Weisz lend their voices to characters in the upcoming Simpsons episode, "How Munched is That Birdie in the Window."
Added:
Lisa stands up for Mr. Burns on the upcoming Simpsons episode, "The Fool Monty."
Added:
Marge makes a big sacrifice for her daughter in the upcoming Simpsons episode, Lisa Simpson, This Isn't Your Life."
Added:
Daniel Radcliffe lent his voice to Edmund during a Twilight parody for The Simpsons' "Treehouse of Horror XXI."
Added:
This is the animated version of Hugh Laurie, courtesy of his 11/7/10 guest-starring gig on The Simpsons. Not much of a resemblance is there?
Added:
Daniel Radcliffe lends his voice and appearance to the November 7 episode of The Simpsons. He comes on board as a character named Edmund.
Added:

The Simpsons Quotes

(Picking out a Tuxedo for Bart. He doesn't look pleased with his puffy shirt tuxedo.)
Bart: (frowning) Isn't this shirt kinda gay?
Clerk: Last time I checked, pirates weren't gay.
Homer: Eww, how'd you check?

Wow, now I see why they call you Miss Hoover. You must have been vacuuming for an hour.

Bart