Staurt over at http://strangemagic.robertsongames.com/2011/10/big-thrills-with-cheap-monsters.html
Mentions a good point about using rubber monsters for minis.
I am always on the lookout for new beasties for my mini collection.
Some of the repurposed items i have are
Bag of bugs
Tube of horses
Party grab bag butterflys (some with wings removed make great giant ants)
My sculpity stuff
Mage knight figs , DC hero figs , Dream blade figs WoW figs ...etc here is a pic of part of my mini cupboard.
I forgot the Heroquest set of furnature and monsters.
So remember you can find minis in most toy sections... dollar stores usually have plenty of rubber monster bags.