OCModShop published a review of the Novus Professional Scratch Remover.

Quote from the review: "Any consumer of computer gear, gadgets, or home theater equipment knows that their stuff starts to look a little worn after a while. It doesn't take long at all before your shiny new iPod gets a few unsightly scratches, diminishing its value and distracting from the gadget's coolness. PC enthusiasts can carve deep gouges in their cases during the course of system maintenance. Let us not forget that scratches can also destroy data on those new BluRay and DVD discs. All of these minor scrapes and scratches not only make your equipment look dated, but lowers its value.

There are a few plastic polish products out there (usually marketed as a CD restorer), but from my experience they just don't work. If you want to completely eliminate any trace of a scratch, then you need a professional product. Novus makes a 3-step plastic polish, which is sold direclty to plastic fabrication shops, and claims to restore plastic, lucite, plexiglass, acrylic, and just about any other plastic polymer to its original finish."
Read the full review on OCModShop.