Have you ever wanted "the one who knocks" to threaten "those who would dare call"? Starting Oct. 7 to Oct. 13, a limited number of 20-second long MP3 messages you write will be recorded by celebrities such as Cher, Peter Dinklage, Mark Hamill, Adam West, Zachary Quinto, and yes - even "Breaking Bad's" Bryan Cranton (aka Walter White/Heisenberg). 

The price for such an honor? $299. All of the money raised will benefit the advocacy group Austism Speaks; which raised over $100,000 last year with its first voicemail fundraiser. According to the site, up to 50 custom messages per celebrity are available. Messages are sold first come, first served and cannot be resold, re-auctioned or returned. 

Last year's participants included Betty White, Will Ferrell, and Patrick Stewart. "This is Sir Patrick Stewart bidding you good tidings," the actor says in one recording. "Unfortunately, Jay is unavailable at the moment. You could leave a message, but we both know it would be nowhere near as awesome as this greeting."

"We decided that bringing together a group of celebrities with great voices to do a kind of 'voiceathon' would be a fun way to raise awareness and funds for the autism community," said actor Ed Asner, whose son, Matt, serves as executive director of Southern California for Autism Speaks. "The campaign was such an overwhelming success and received so much positive feedback we had to do it again."

Want one? Jump here to learn more about the campaign and how to purchase your recording

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Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Walter White will record your voicemail greeting for charity
Bryan Cranston, Cher, Jack Black, Peter Dinklage sign up to record custom voicemails for Autism Speaks.