Have just found an interesting website.
JustGiving.Com! is a site set up to help anyone raise money for charity, and they have a Celebrity page.
You could sponser Simon Biagi for Children in Crisis, Alastair Campbell for Leukaemia Research Fund, Gary Lineker for Leukaemia Research Fund, Dan Radcliffe for National Autistic Society Alan Rickman for Royal Academy of Dramatic Art (RADA) or more.
My favourite one when looking through was Sissy Rooney (BB4) for Children in Crisis who has been sponsered by none other than her Housemate Mr. Jon Tickle.