You ain't seen nuthin yet
Back in my college days, I used to work for a small IT company that had a sideline business in recycling and reconditioning old PCs. This was back in the day when smoking in the office was positively encouraged. Some of the horrors you'd find when you opened the case - it was as though one of the staff had removed a lung and inserted it between the IDE and VGA (ok, Hercules) cards. The fans had continually sucked the stuff into a pile for so long you could remove it as a solid block of exhaled cancer.
I'm sure somebody else from "back in the day" will be along with pictures.
Paris, because she can suck stuff into a pile for so long that.... Um... Never mind...