Apple iPad Anti-Glare Matte Finishing Screen Protector for $0.99 after applying coupon code IPADANTISCREEN.  Shipping is $2.85, so the total comes to $3.84 shipped.  Here is a screenshot for your reference.  It is designed to perfectly fit the iPad screen and attaches with a self-adhering surface that leaves no residue when removed.  The matte finishing surface protects the iPad from scratches and dust and does not effect the touch screen.