But over the years, something has happened to movie trailers. Technically speaking, they've always been more of a science than an art -- after all, they're designed to put fannies in seats, and not much more. But sometimes they could feel like art, if only in the way they sent a charge through you, building anticipation for something new and potentially thrilling.

But now, more often than not, they only sap your will to live. The trailers for most action movies are interchangeable, featuring various combinations of car crashes and explosions and snippets of dialogue showing this or that actor looking deeply concerned. The trailer for "Gone in 60 Seconds," the new Jerry Bruckheimer actionfest, is a haphazard daisy chain of the expected joy rides and collisions, a noisy procession of vehicles peeling out and spinning out, but in the end it's curiously inert. Even as it overloads us with visual cues, it doesn't tell us nearly enough. The trailer doesn't build any momentum; there's plenty of movement and commotion in it, but it's so unfocused, so reckless in its attempt to grab us, that any excitement it might have generated ends up being diffused and shattered like plate glass.

Part of the problem with trailers may be that we just get too many of them. One or two per movie used to be the norm; now we sit through a wearisome parade of four or five. And we've all seen trailers for comedies that give away every good gag, or run through every significant plot point, right up to the conclusion. Those authoritative voice-overs that outline the premise in storytime-for-kindergartners terms don't help.

Ideally, there should be something pleasurably anticipatory about movie trailers. They're a glimpse of something you've never seen before (even if, in the broad sense, you have seen it before), like miniature portals into your moviegoing future. When they're done well, they can be works of art in themselves. I never saw the trailer for Albert Brooks' 1979 "Real Life," in which Brooks announces that the trailer will be shown in 3-D but only in certain theaters, and that those in the unequipped theaters (that is, all of them) should turn to their neighbor and ask to borrow two pieces of red and blue cellophane. But I can easily understand why, among the people who've seen it, it has become the stuff of legend.

And yet even if we feel bludgeoned by trailers, or insulted by them, or annoyed by them, most of us still pay attention to them, whether we admit it or not. As sophisticated as most of us claim to be about all other kinds of advertising, movie trailers have nestled themselves into a separate and very special category in our brains. They're among the most blatant forms of marketing in the media: The fact that we're happy to point out all their faults proves that deep down we know that they've been conceived, crafted and test-marketed to get to us.

Most of us would blanch at the idea of buying, say, a roll of paper towels or a bathroom cleanser just because a commercial jingle had lodged itself in our heads, but almost all of us (including critics -- we'll get to them later) have at one time or another made a confident-sounding pronouncement about a movie we haven't yet seen, based solely on the trailer. Even the most rudimentary and blatantly sales-minded trailer gives us hard information about a movie's stars or its jokes or how many car crashes or explosions it might include. But those trailers also contain a kind of embedded code, information that's carefully massaged by the studio, and often fueled by its paranoia about how its product will be perceived. A trailer can be edited to make a movie look completely different, or at least significantly different, from what it really is.

Yet most of us, after seeing a trailer, tend to feel we have a reasonable idea of what a movie is about -- in other words, we're right where the movie industry wants us. We've mistaken information for knowledge.

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