I just came across this video and thought it would be great to share. According to the map on deaddrops.com there aren't any listed in Madison, WI. I might have to change that.
"Dead Drops" is an anonymous, offline, peer to peer file-sharing network in public space. USB flash drives are embedded into walls, buildings and curbs accessable to anybody in public space. Everyone is invited to drop or find files on a dead drop. Plug your laptop to a wall, house or pole to share your favorite files and data. Each dead drop is installed empty except a readme.txt file explaining the project. ‘Dead Drops’ is open to participation. If you want to install a dead drop in your city/neighborhood follow the ‘how to’ instructions and submit the location and pictures.