I took this photo just for this thread!
We were in Seattle for a couple days, and I wandered down to Pike Place Market, which is one of my favorite ways to kill time while waiting for my wife, who was shopping.
The "Gum Wall" is both fascinating and disgusting at the same time. The city cleaned the alley down to bare brick a while back (you can google before and after photos), but now it's almost back to its original glory.
I chewed a pack of Juicy Fruit once, and stuck a quarter to the wall. My next trip down there, the quarter was gone!