1 Only you: Human lips are different from those of all other animals because they are everted, meaning that they purse outward.

2 But we are not the only species to engage in kissing-like behaviors. Great apes press their lips together to express excitement, affection, or reconciliation.

3 Scientists are not sure why humans kiss, but some think the answer lies in early feeding experiences. Through nursing and (in some cultures) receiving pre-chewed food from a parent's mouth, infants may learn to associate lip pressure with a loving act.
3 Size matters. At the nano scale, materials take on unusual properties. Their color, transparency, and melting point often differ significantly from those of larger clumps of the same stuff.

4 Nanoscale bits of metal oxide, carbon fiber, or metal blends can detoxify hazardous waste: Their extreme solubility and chemical reactivity help them zero in on the nasty stuff.

5 This approach is already being used at sites in a dozen states, mostly to clean groundwater fouled by solvents, metals, and petroleum.

6 Brighter colors! Richer flavors! Less spoilage! Those are some of the reasons why companies are dumping nanoparticles into hundreds of products, including cosmetics, sunscreens, and food.

7 Analysts say the global market for manufactured goods using nanomaterials could hit $1.6 trillion by 2013.

8 Uh-oh. Studies show that nanoparticles can work their way into the bloodstream, penetrate cells, and get past the blood-brain barrier. Research has linked such particles to lung damage; the brain may be affected too.

9 But if those particles don’t kill us, they just might save us. Scientists at U.C. San Diego have designed a fluorescent nanoparticle that glows inside the body, making it easier to image tumors and organ damage.

10 Yale researchers have created plastic nanospheres that encapsulate proteins called cytokines, which stimulate the immune system’s killer T-cells. An injection of those spheres could help fight disease and infection.

11 And in a University of Southern California lab, nanotubes have been used to create synthetic neurons (pdf).

12 The USC team is trying to assemble these neurons into functional networks, which would bring us closer to assistive brain implants.

13 In 1989, using an atomic force microscope, IBM engineer Don Eigler became the first person to move and control a single atom.

14 Eigler and his team later used 35 xenon atoms to spell out “IBM,” thus performing the world’s smallest PR stunt.

15 Atoms? Big whoop. Researchers at Princeton and U.C. Santa Barbara can control the spin of a single electron, trapping it in a “corral” created by applying voltage to minuscule electrodes.

16 But they’re not playing cowboy. The breakthrough could lead to powerful quantum computers that store and manipulate data in the spin of individual electrons.

17 Not to be outdone, Stan­ford scientists used scanning tunneling microscopy and holograms to write information within the interference patterns formed by electron waves on a copper sheet. The letters are less than a third the size of Eigler’s “IBM.”

18 Government researchers have created arrays of chromium nanodots that can store magnetic data with unprecedented uniformity. One goal: drawing more complex integrated circuits on silicon chips.

19 For the rodent who has everything. Georgia Tech scientists made piezoelectric generators out of nanowires and attached them to tiny hamster jackets. When the critters ran, the generators created electricity.

20 Zhong Lin Wang, co-inventor of the jacket, envisions a shirt that charges your cell phone as you stroll, or an implanted device for measuring blood pressure that’s powered by your own heartbeat.