The DVD Coach Single Target Duplicator by EZ Dupe is both a mouthful and a computer-free solution for creating copies of DVDs and CDs. Just put whatever disc you want duplicated into one drive and a blank one in the other and — voilà! — you've got two discs of the same. If you do end up plugging it into your machine, the DVD Coach will still do its job with the added bonus of functioning as a Lightscribe CD labeler, printing a custom image onto the surface of your disc.
The ability to burn on the go comes at a price, however, and it'll cost you anywhere between $340 to $460. Considering drives that do the same thing (albeit computer-bound) costs well under the $100 mark, you'll have to decide for yourself if the extra money is worth it.