It seems there is a thriving market for collecting aluminum bottles. A search on ebay shows over 2,300 listings for aluminum bottles. There are listings for sets of bottles as well as individual bottles.
The custom Coke aluminum bottles made for the 2010 Shanghai Expo is a case in point. These bottles are being sold at $40 a piece on ebay! There are even price differences for opened vs unopened bottles.
It seems the aluminum bottle is becoming a minor cultural phenomenon.