For parents, this time of year can feel like walking through a minefield, with ads, decorations and music all aimed at getting kids excited about Christmas. Every year children eagerly ask Santa for the “hottest,” “must-have” toys – and then turn that “pester power” on their parents.

Why is a movie about a young boy learning kung fu called The Karate Kid? For most of the film's young audience, Jaden Smith's break-out movie doesn't explain the confusion. Their parents and older siblings, however, may recall the earlier installments in this series which started with a young Ralph Macchio learning karate from Noriyuki “Pat” Morita, a movie which started as the hero's quest to learn karate to overcome his tormentors and evolved by film's end into a coming-of-age story about the bond between mentor and student. The first Karate Kid struck a chord with audiences, becoming the fifth-highest grossing film of 1984.

People who make their living producing images, such as photographers, stylists, publicists, directors and pop idols, learn how to use those signs to convey the impression they want to make. Although teen girls who are trying to send a signal to their circle of friends and pop music producers who are trying to send a signal to an audience of millions are working on different scales, the principle is very much the same. Depending on your audience, you need to tailor the signals you send out very carefully. Even your age can have a certain amount of wiggle room when dressed in the right signs.

New York's Gramercy Park is a curious institution: two acres of fenced-in greenspace that is accessible only to those who own the houses surrounding the park. (Non-residents must either stay at the Gramercy Park Hotel or join the Players Club or National Arts Club if they want to visit, and each of these institutions has a limited number of park keys.) Private parks like it are the exception, of course, not the rule: since the days of Frederick Law Olmsted, who campaigned for and designed city parks across North America (Central Park, in New York, and Montreal's Mount Royal Park among them) we have come to expect most of our recreational spaces to be public. Cities and neighbourhoods are routinely rated on both the quantity and quality of their parks, and any suggestion that these services should be cut back always receives violent reactions from taxpayers; playgrounds, too, are public by default.

It's a question that most parents of young daughters face: "Has she hit the 'princess phase' yet?" Not all parents are upset by this, of course: many happily buy their girls princess costumes, toys and accessories ranging from shoes to purses, all in pink. Some, though, despair of the powerful gender stereotyping this delivers to young girls and each new piece of princess gear can be a source of conflict.

On Saturday, September 26, 2009, the US network Nickelodeon did something unusual: it switched itself off. This was in observance of the "Worldwide Day of Play," an event Nickelodeon inaugurated in 2004. The network -- along with its sister channels Noggin, the N, and Nicktoons, and their associated Web sites -- went dark for three hours to encourage its young viewers to "ride a bike, do a dance, kick a ball, skate a board, jump a rope, swing a swing, climb a wall, run a race, do ANYTHING that gets you up and playing!"

Last year in this space we wrote about how summer movies serve as advertisements for various kinds of merchandising. The success of 2007's Transformers and its sequel this summer point to a different but similar trend: making movies that are actually about the toys companies sell.

It's been widely said that attention is the currency of the 21st Century. In an age where media occupy an increasingly central role in our lives, the need to have that media focused on you becomes intense. For no-one is this more true than for children and teens, who now expect to be connected twenty-four hours a day and for whom the Internet and cell phones are essential parts of their social lives. An interesting Facebook page, amusing Tweets, outrageous YouTube videos, even shocking photos sent by cell phone -- most of us are aware of the ways that young people seek their peers' attention. In today's media environment, is it still possible to teach young people the value of privacy? What, indeed, does the idea of privacy even mean to today's children and teens?

It's a persistent phenomenon: the faster we move into the future, the more we find it embedded with the bones of the past. Why else, for instance, would we still talk about “dialling” a phone, and later about “hanging it up”? Few people remember the early TV remote controls that worked by sending high-frequency sounds, but we still call remotes “clickers.” We still say “stay tuned,” “CC” (carbon copy) e-mails, “rewind” DVDs, and “post” online messages. Even new media darling YouTube contains an old-media artefact of this kind: the name is obviously meant to make us think of television, the “boob tube,” but few TVs have tubes in them anymore.

There's an old urban legend called “the water engine,” which tells of the discovery of a way to turn water into fuel. There are variations to the story – sometimes it's tap water, sometimes sea water; in recent versions it's specified the fuel is nonpolluting – but the ending is always the same: the invention is suppressed by the oil companies, either by buying the invention and burying it or by forcing the inventor into ruin and suicide. One reason the legend has persisted so long – it's been recorded as early as the 1950s, and probably dates to the first time someone grumbled about the cost of filling up his car – is because it confirms something we already believe, which is that the oil companies are evil and would rather murder a man and doom the world than sacrifice a dime of profit.