THE SIMPSONS: Homer Simpson as an avid stamp collector on THE SIMPSONS on FOX. THE SIMPSONS Trademark and Copyright 2009 TTCFFC ALL RIGHTS RESERVED. Copyright 2009 FOX BROADCASTING CR: FOX

The Simpsons themed U.S. Postal Service stamps are unveiled at the first day of issue ceremony at 20th Century Fox Studios in Los Angeles on Thursday, May 7, 2009. (AP Photo/Damian Dovarganes)
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THE SIMPSONS: (L-R) Cast member Dan Castelanetta at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: Executive producer James L. Brooks and cast member Yeardley Smith at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: Cast members Nancy Cartwright (L) and Julie Kavner (R) sign stamps at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: Creator and executive producer Matt Groening signs The Simpsons stamps at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: Host and cast member Kelsey Grammer at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: (L-R) Creator and executive producer Matt Groening and cast members Nancy Cartwright, Dan Castelanetta, Julie Kavner and Yeardley Smith sign stamps at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, …

THE SIMPSONS: (L-R) 20th Television Chairman Gary Newman, creator and executive producer Matt Groening and cast members Kelsey Grammer and Nancy Carwright at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. …

THE SIMPSONS: (L-R) Host and cast member Kelsey Grammer, executive producer James L. Brooks, creator and executive producer Matt Groening and cast members Nancy Carwright, Yeardley Smith, Dan castelanetta and Julie Kavner at The Simpsons …

THE SIMPSONS: Creator and executive producer Matt Groening and cast member Nancy Cartwright at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

Matt Groening, creator and executive producer of "The Simpsons" autographs a Simpsons-themed U.S. Postal Service stamps, as they are unveiled at the Twenty Century Fox Studios in Los Angeles on Thursday, May 7, 2009. (AP Photo/Damian …
Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

THE SIMPSONS: (L-R) Creator and executive producer Matt Groening, executive producer James L. Brooks, and USPS Vice President, Ground Shipping Jim Cochrane unveil The Simpsons stamps at The Simpsons Stamp Ceremony at Fox Studios in Los …

THE SIMPSONS: Fans of THE SIMPSONS at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: Fans of THE SIMPSONS at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: The USC Trojan Marching Band during The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

THE SIMPSONS: New stamps featuring THE SIMPSONS that became available to fans at The Simpsons Stamp Ceremony at Fox Studios in Los Angeles, CA., Thursday, May 7. Copyright 2009 FOX BROADCASTING CR: Michael Yarish/FOX

Nancy Cartwright, the voice of Bart Simpson, signs a poster at the unveiling of the new "The Simpsons" U.S. postage stamps at the Twenty Century Fox Studios in Los Angeles on Thursday, May 7, 2009. (AP Photo/Damian Dovarganes)
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Characters dressed as The Simpsons, from left, Bart, Marge, holding MAggie, Lisa and Homer pose as the U.S. Postal Service "The Simpsons" stamps are unveiled at the Twenty Century Fox Studios in Los Angeles on Thursday, May 7, 2009. (AP …
Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Yeardley Smith, the voice of Lisa Simpson, signs a poster at the unveiling of the new "The Simpsons" U.S. postage stamps at the Twenty Century Fox Studios in Los Angeles on Thursday, May 7, 2009. (AP Photo/Damian Dovarganes)
Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

The 44-cent stamps from "The Simpsons" television show are displayed at a post office in Palo Alto, Calif. on Monday, May 11, 2009. The price of a first-class stamp for mailing a letter - or paying a bill - climbed to 44 cents Monday, …
Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.