I made stock last night.
One lot of chicken, turkey (had a turkey leg from Son of Maurice that I think might have been a dinosaur haunch) with some hard cheese rind (Parmesan or similar) - top tip I got from newspaper cooking online column, adding cheese rind to your stock.
The other lot was crab shells and legs. Can't do the wazzing it all up and seiving it as I only have a stick blender at the mo, so just strained it and chucked it in the freezer. It will come in handy. 
No marzipan was harmed in this post.