Yes, people collect all sorts of things, but check out these fabulous bird cages from around the world. Some are now worth a small fortune, but whatever you do, don't show these to your pet canary. He might become disgruntled if he's sitting in some crappy wire or cane construction you purchased cheaply at the local pet shop.
Clancy's comment: Extraordinary quality, eh? And, as you can see, my favourite cat above is viewing them with a keen eye.