A hallmark of David Foster Wallace's style: the transposed cliché. He takes some phrase or figure that is popular or automatic in American parlance and either (1) transfers it to another semantic domain or (2) synonymizes it, so that it takes on a new specificity or emphasis.
One example for now, from the Rolling Stone profile of John McCain, already cited by Douglas Wolk:
when one of the Twelve Monkeys interrupts to ask whether it'd be fair to characterize this new ad as Negative Murphy gives him a long styptic look and spells "r-e-s-p-o-n-s-e" out very slowly.
"A long styptic look": what this means is clear from the context (a nasty, dismissive, deflating kind of look) but Wallace adds some zest to it with the word "styptic," as in styptic pencil, meaning "contracting the tissues or blood vessels; astringent." Wolk describes this as a "perfect word that comes out of nowhere," but in fact I think it's fairly easy to guess where it came from. One imagines this phrase might have started life as "a long withering look," only to be rejected by Wallace as being too stock. But rather than change the basic meaning, he gets out the (mental?) thesaurus to find a more energetic, recondite word to express a conventional meaning. Hence "styptic," which adds some unpleasant clinical associations but basically maintains the original sense, just boosting it up into a higher register.
I don't mean this necessarily as a criticism of Wallace, that he merely substitutes high-status verbiage ("uptown words," as he puts it somewhere) for basically homely sentiments — although I think the criticism could be made. But I think it's a procedure intrinsic to his writing, and in a serious analysis of him there would be worse places to start.
More examples to follow, when I get around to reading Wallace again.