Having a decent background makes all the difference when you're doing still photography, like product shots for eBay. Everyone knows that your crappy "vintage" shirt looks better in a studio setting rather than just on your bedspread.
This D-Flector Photography Studio in a Suitcase makes taking pro snaps easy and cheap without having to own your own studio. Just open it up, plop your item down on it, and shoot away. Now your photos will look professional, even when you clearly aren't.