This one didn't take a genius, but the results are genius, and we plan on covering the box spring in our guest room today thanks to this tip. Benita at Chez Larsson offered a great how-to for a streamlined bed skirt, and the following idea from Martha Stewart is an even more basic solution:
From Martha Stewart online:
If you want to dress up your bed but find dust ruffles a bit fussy, consider slipping a fitted sheet over your box spring for a streamlined look.
Even a mismatched fitted sheet could work -- spicing up the color or pattern combos on the bed. Anyone been using this trick for a while now, liking or disliking the results/effect?