More and more people these days do the latter. Phones are the new wristwatch.

But in the 19th and 20th centuries, timepieces were the dominant mobile must-haves. Victorian-era gentleman wouldn't be caught dead without their pocket watches. These marvels of miniaturization conveyed status, wealth and modernity. Using a pocket watch told the world that our great-great-great grandfathers were in touch with the efficient, time-obsessed Industrial Revolution. One checked the time frequently, then snapped the clamshell gadget shut and returned it to its place of honor with a single, well-practiced motion -- just like people do today with clamshell cell phones.

The pocket watch was cool, in a handlebar-mustache-and-monocle kind of way, but the form factor was ill-suited for the trench warfare of World War I. Pocket watches could be too easily lost or damaged in the field of battle, and they required an empty hand to use. Although first sold as women's accessories in the late 19th and early 20th centuries and called "wristlets," WWI artillery officers on both sides were issued wristwatches as military equipment, which they were allowed to keep after the war. Initially called "trench watches" because they were associated with trench warfare, wristwatches became required accessories for businesspeople during the rest of the century.

But the mid-century microprocessor revolution, and the miniaturizing march of Moore's Law, eventually brought two revolutionary changes: the cell phone and the wristwatch-based computer. Cell phones make calls, of course, but do so much more: They take pictures, keep your schedule, enable you to send text messages and many other things. And they keep the time.

Since everyone has a cell phone that displays the exact time on the main screen, why lash some anachronistic clock to your wrist? A growing number of people are just going without a wristwatch -- including me.