On celebrity endorsements, who are behind (a) luxury brands and/or (b) social causes?

[CRimando]

I'd like to know as many celebrities as possible who are (or have been) allowing their names to be associated with charity or social/environmental responsiblity causes i.e AIDS, Greenpeace, etc.
While on the subject of celebrity endorsement, may I also ask who have been the famous ones that became the face that reinforced the marketing efforts of big and successful luxury products.
Thank you.

[bigcellar261]

Angelina Jolie