Piles are an interface concept patented in 1994- you make piles of documents, and piles with more content would appear bigger… so now you could have a cluttered Desktop on your computer as well as in real life!
Although, one thing that would be pretty cool- when an items is in “piles”, you can have something in multiple piles at once, unlike on your real-life desk.Here’s sort of a ranty article from Ask Tog
Web link of note: Piles demo
(At http://homepage.mac.com/rdas7/piles.html)