Used to be that men had only two choices when it came to underwear: boxers or briefs. These days it's also a toss-up between vitamin C and ginseng-enriched. Developed by aspirin giant Bayer for Aussie Bum's Essence line, these undergarments contain either ginseng or acerola (a tropical fruit rich in vitamin C and other antioxidants) that is woven between the fabric fibers and then released into the skin. Vitamin C offers protection for your skin (and eliminates that cold, clammy feeling when working out), while ginseng energizes and regenerates. Though the company doesn't claim the underpants could energize onlookers, we're betting otherwise. Order the downright skimpy skivvies from down under at aussiebum.com. —Karen Ashbee