New York, NY -- How cool would it be to have Tom Hanks tell people who call you to wait for the beep? Or William Shatner, Betty White or Will Ferrell? They'll say whatever you want in a 20-second message, as long as it's not dirty. It'll cost you nearly $300, with the money going toward autism research and advocacy efforts by the group Autism Speaks. A limited number of the messages will go on sale from December 3 to December 9 on a first-come, first-served basis.