Obama does it. And increasingly, so do folks around the world. Why is the fist bump so popular? And do other cultures have similar gestures?
Also in this week's tech headlines: Visa looks to boost online shopping, a Wall Street cyber scare, and fears that driverless cars could be used as "lethal weapons."
At the time, ideas of race in America were quite literally black and white. But a few meters of cloth changed the way some people of color were treated.
The Department of the Interior might not have the largest Twitter following among federal agencies, but its account might be the most loved of all.