Yes, tools for dental hygiene make an unorthodox gift, but one Pop Sci editor evangelizes this stuff. "Dr. Tongue: it changed me," she says. Here's the deal: the floss expands when it's between your teeth, so it removes up to 55 percent more plaque "than some of the most popular flosses," or so the marketing copy claims. Plus it's waxed with vegetable and bee waxes rather than the petrochemical stuff. Oh, and the package is biodegradable, too. $7 for 30 yards.