Left Behind

Some are taking it a few steps further. With virtual reality programs such as Second Life, people create avatars of themselves and go on to have illicit affairs and even long-term relationships, often conducted solely with staccato onscreen messages.

Of course, a certain level of intimacy is lost. Giggles are gone; pauses all the more fraught. (Is he transported by passion . . . or IMing another girl concurrently?)

While it's doubtful these media could ever threaten the popularity of the actual act, there's no shortage of people eager to experiment with them. According to a survey conducted in Canada for the site Campuskiss.com, more college students take part in instant-messenger sex than in any kind of telephonic sex.

Because love means never having to say, "Can you hear me now?"

Getting Lost

b. dawn of man -- d. 1990s

In 1983, President Ronald Reagan decreed that the Global Positioning System, theretofore the provenance of the military, would be open to the public. Little did the Gipper know that this decision would affect the lives of untold numbers of couples, all habitually deadlocked on whether to ask for directions.

In an era where "MapQuest" is a verb, having no sense of direction or ability to read a map have become excusable flaws. You can almost count on having a GPS nearby. The technology-focused market research company Forward Concepts reports that 171 million units were shipped last year and more than three times as many will ship in 2011. Though most of the devices are embedded in cars and phones, they're also helping people keep track of meandering pets, kids and impaired adults.

But, if life truly is about the journey and not the destination, losing "lost" could be a real loss. Consider the ramifications on Western culture had the technology popped up sooner. Would there be The Odyssey? Columbus might've actually found the Orient ("Make the next legal U-turn").

Losing sight of our meandering ways and the connections made with people during unexpected sojourns may be the biggest loss of all. What happened to directions scribbled on cocktail napkins? Or, for that matter, spontaneity? Used to be half the joy of a family trip was spreading out the map on the dash, strapping the dog to the roof and admitting you had no way to answer the age-old question: "Are we there yet?"

On the flip side, depending on what GPS voice features your device offers, today you may be able to avoid familial conflict by letting Mr. T tell the kids exactly how far there is to go.

Cash

b. pre-600 B.C. -- d. early 2000s

Take a good whiff of a greenback -- if you actually have one in your wallet, that is. The aroma might just take you back to a time of savings passbooks (in lieu of online banking), rolling quarters (instead of hitting the Coinstar machine) and trips to Europe when you could actually afford a madeleine.