Ability to create folders in collection

It would be nice to be able to create folders to organize the cards in our collection.  An example would be to create a folder for each player or sport and have the results show on the left side in alphabetical order.  Or you could create folders of potential cards you want to sell or ones you may want to get graded.  There are a few sorting features but it still doesn't narrow the results down very much.  

Another feature that would be nice would be being able to tag cards with whatever color you want so it's easy to see when you go into each folder.