For all of you with old cassette cases gathering dust in a box, why not pull one out and use it to store your earbuds when you're not jamming out in the real world?
Wind up your cord and sit it within the case where the nubs stick out. You can use other cases to hold other cords and label the outside so you know exactly where your iPod cord is the next time you go tearing through the house looking for it.
Other uses for old cassette tape cases? To catch insects!