Book Sox
   Stretchable fabric book covers for hard-covered books.
   http://booksox.com/

BookWrapz
   Stretchable book covers for all sized textbooks.
   http://www.bookwrapz.com/

Gotcha Covered
   Handcrafted cloth book covers.
   http://www.clothbookcovers.com/

Stretch Text
   Stretch fabric book covers that are reusable and washable in a wide array of designs.
   http://www.stretchtext.com/