Celebrities supporting charities

[Jen33]

Hi

I live in Australia. My daughter had cancer at 12 she is well now and studying medicine. I now work with a charity now that aims to raise money for childhood cancer research. Does anyone know of any celebrities that are good at responding to requests for donations of autographs for us to raffle off. I've had a few Australian celebrities respond but no success with the American ones. Any tips.

Cheers
Jen