These are the things that when you see them, you think "genius" and "how simple but awesome." Hopefully I will use them in the future.
Toilet paper rolls (or paper towel rolls) to store cords! At the site where I found this, storage glee they have tons of crazy designs including a kitchen made of drawers.
Of course this one is from Martha Stewart Kids
Aptly from Real Simple's Summertime New Uses For Old Things
You can never have too many shelves (unless of course you're trying to toddler proof your house)