nbren007's request for something for the wishlist gave me the idea  - what do people think of having different layouts for each of the tabs?
So you could have your owned collection laid out one way, your ordered collection another, your wish list another way again.
That way - an idea anyway - you could have an HTML window containing a list of price comparison sites that only displays in your wishlist.
You could have an HTML window in your ordered tab that displays a link to the shop in question so you can keep tabs on your order.
If you find that all your wishlist titles don't have covers yet, you could switch them off but still keep them in your ordered and owned windows.
I'm sure others can think of other ways this could be handy.