The above photos of Adam Horovitz and Adam Yauch were taken last fall in Denver by an artist, who simply credits himself as "Rick," for his Portroids project (portroid = portrait + polaroid). The artist's idea is to shoot one polaroid photo of interesting people he meets and have them sign the polaroid before it develops. Visit the Portroids.com celebrities page to see the full-sized portroids of Yauch and Horovitz.
In the artist's blog, he describes his encounter with the two Beastie Boys:
MCA wanted to know if I have a portroid of David Lee Roth (I don't). Adrock wanted to know if I have a portroid of Richard Simmons (sadly, no).
I did not meet Mike D, so don't even ask. Thank you.