A video where someone (Black Thought) puts on more and more t-shirts.

Each shirt goes over the last shirt. Shirts start at size S and go to 10X.

Only the first two shirts are shown being put on the rest just appear ala I Dream of Jeanie.

The shirts can have messages that go with the song ala Bob Dylan's Subterranean Homesick Blues video.

This idea is ripped directly form the Gusiness book of World Records.

This could be done practically or via CGI. if CGI you could track around the guy ala Untitled by D'Angelo.

I steal all these ideas ala a guy with too much time on his hands ala Foreigner.
Here's a video of the guy who originally did it:
http://www.youtube.com/watch?v=r6tlw-oPDBM