As part of our year-end wrap-up of the biggest science stories of 2008, below we present the 10 most-viewed stories on over the past year. The selections run the gamut, from everyday human concerns (love, sex and procrastination) to the big questions (death, the nature of time, evolution versus intelligent design). Issues of digital security and trust ranked high as well—including Herbert H. Thompson's first-person account of stealing an identity and Hany Farid's guide to spotting manipulated photos. Alternative energy, always a hot issue, makes an appearance, as we examine the future of biofuels beyond corn ethanol. And, just for good measure, we consider the possibility, however remote, that Batman might really exist.

10. Affairs of the Lips: Why We Kiss
Researchers are revealing hidden complexities behind the simple act of kissing, which relays powerful messages to your brain, body and partner.

9. Grass Makes Better Ethanol Than Corn Does
Midwestern farms prove switchgrass could be the right crop for producing ethanol to replace gasoline.

8. Procrastinating Again? How to Kick the Habit
Although biology is partly to blame for foot-dragging, anyone can learn to quit.

7. Does Time Run Backward in Other Universes?
One of the most basic facts of life is that the future looks different from the past. But on a grand cosmological scale, they may look the same.

6. The Orgasmic Mind: The Neurological Roots of Sexual Pleasure
Achieving sexual climax requires a complex conspiracy of sensory and psychological signals—and the eventual silencing of critical brain areas.

5. Never Say Die: Why We Can't Imagine Death
Why so many of us think our minds continue on after we die.

4. Six Things in Expelled That Ben Stein Doesn't Want You to Know...
...about intelligent design and evolution.

3. How I Stole Someone's Identity
The author asked some of his acquaintances for permission to break into their online banking accounts. The goal was simple: get into their online accounts using the information about them, their families and acquaintances that is freely available online.

2. Dark Knight Shift: Why Batman Could Exist—But Not for Long
Q&A with movement researcher E. Paul Zehr.

1. Digital Forensics: 5 Ways to Spot a Fake Photo
Digital forensics expert Hany Farid runs down the telltale signs of photo doctoring.

Photo credits: © iStockphoto/Simon McConico Photography (10); Courtesy of USDA-ARS (9); Getty Images (8); © iStockphoto/Mark Evans (7); © iStockphoto/Vasiliy Yakobchuk (6); Robert Stahl/Getty Images (5); Kelly Engstrom (4); Courtesy of Herbert H. Thompson (3); Warner Bros. (2); SciAm staff (1)