Backseat Film Festival (Fri.-Sun., Jan. 23-25, Triangle Theater, 1220 N. Lawrence St., www.backseatfilmfestival.com) Plunging its flag into the frozen terrain of Northern Liberties, the Backseat Film Festival pulls over for three underground film-filled days and nights. These days, "underground film" is as much a genre as anything else, which means there's a certain predictability to the BFF's entries (not to mention a few overlaps with the Lost Film Festival): Rusty Nails' heartfelt but redundant tribute to The Ramones, a smattering of Bill Plympton, a trailer for Punk Rock Holocaust, a no-budget murder mystery set on the Warped Tour. Ah, cross-promotion! (Did we mention it's produced by the festival's organizers?)

Still, any chance to see Jessica Villines' fantastic Plaster Caster is worth welcoming. Part of Saturday afternoon's "I Love Rock 'n' Roll" program -- which kicks off at 1:30 with An Incredible Simulation, a tribute to tribute bands -- Villines' documentary tells the story of Cynthia Plaster Caster, who for more than three decades has been convincing rock stars to make molds of their privates for her not-so-private collection. Though a legendary figure, Cynthia is usually no more than a footnote in the official history; I was more than halfway through the film before I realized I'd never even considered that she might have a real last name. Plaster Caster preserves that piece of anonymity, but you'll learn plenty more, from her preferred casting material (dental amalgam) to who really has the biggest dick in rock. (Jimi Hendrix, but you knew that.) Not (or at least not merely) a groupie or fame junkie, Cynthia comes off as a true artist, and not just because the film leads up to the first-ever public exhibition of her work. She talks about the "virginal femininity" of her plaster reproductions (or, as she puts it, "my sweet babies"), scraping out a living rather than exploiting her fame. (In one of the film's more painful scenes, she admits to taking $100 each month from her mother, who at 84 is still unaware of her daughter's subterranean celebrity.) Not surprisingly, the most fascinating comments and reactions come from the men involved; 5ive Style's Bill Dolan blushes nervously when approached to be cast, flattered to be in the same company with Hendrix, while Momus excuses his somewhat disappointing cast by half-joking that he was "ironically unerect." A word of warning: Think twice about watching if you plan to see Jon Langford at the North Star on Wednesday. After seeing his cast, it'll be awfully tough to look him in the eye.

Modern Times (Thu.-Fri., Jan. 22-23, 7:30 p.m.; Sat., Jan. 24, 7 p.m.; Sun., Jan. 25, 5 p.m., $8.50, Prince Music Theater, 1412 Chestnut St., 215-569-9700) Presented in a beautiful new restoration (the same used for last year's DVD), Charlie Chaplin's 1936 satire positively sparkles. The film's justly enshrined sequences strike out at the dehumanization of assembly-line work (a pressing issue of the day); Chaplin in the gears of that monstrous machine is a perfect hieroglyph, a philosophy condensed into a single delirious image. But though it's sometimes called Chaplin's masterpiece (often, I suspect, by those who value Chaplin's politics more than his artistry), hints of disagreeable self-importance, of Statement, creep in. Chaplin's man of the people (The Tramp in appearance, though not by name) has become an idealized creature: a forest nymph, if not a Daily Worker caricature. Though essentially good-hearted, the eponymous hero of 1915's The Tramp (see below) is still venal enough to pelt enemies with eggs and stick them with pitchforks; he retrieves a damsel's money from a thief, only to consider keeping it himself. By Modern Times, that inner struggle is gone. The gags in Modern Times are more elaborate, less repetitious than The Tramp's (ironic given the later film's emphasis on mechanized reproduction), but the characters have lost complexity: They're puppets in a play. There's an ugliness in the Modern Times scene where Chaplin's factory worker is pummeled by the automated feeding machine that belies the film's antic tone; as the machine speeds up, Chaplin's face starts to blur, and suddenly, it's not funny at all.

Classics of the Silent Era (Sat., Jan. 24, 8 p.m., $6, International House, 3701 Chestnut St., 215-895-6542) Guglielmo Foffani provides live accompaniment for a series of silent short subjects. In addition to Chaplin's The Tramp, whose bittersweet ending ("I thort your kindness was love but it ain't cause I seen him") proved that Chaplin could get more than laughs, there's D.W. Griffith's Corner in Wheat (1909), René Clair's Entr'acte (1924), Joris Ivens' Rain (1929) and the diving sequence from Leni Riefenstahl's Olympia (1938).

An Injury to One (Mon., Jan. 26, 9 p.m.; Fri., Jan. 30, 6:30 a.m. and 5:30 p.m., Sundance Channel) Travis Wilkerson's experimental doc blends a few too many techniques in recounting the story of International Workers of the World organizer Frank Little, who was murdered in August 1917 after leading a drive to unionize Montana miners. While Injury is effective agitprop, Wilkerson's technical sophistication at times merely masks the holes in his logic. There may be a connection between the Anaconda Mining Company's union-busting and the environmental pollution that still scars present-day Butte, but it's not a self-evident one (would a unionized workplace have been more eco-friendly?). Including ominous music by Low, The Dirty Three and others, Injury mounts a powerful argument, but it would be more effective if it sparked debate, and not submission.

The Office For once, you can't blame the Oscars for missing the boat: The greatest performance of last year wasn't even on film. Watching the first season of this BBC import on DVD (and the second on BBC America, and the final two episodes on Internet bootleg), it's clear that Ricky Gervais' David Brent deserves a place in the comic pantheon, elbowing his way between Ralph Kramden and W.C. Fields. The head of a paper manufacturing branch in industrial Slough, Brent fancies himself a "chilled-out entertainer," which, as anyone who's ever had a "nice guy" for a boss knows, is a recipe for disaster. That Brent is a mean-spirited coward at heart is what gives the show its much talked about "edge"; in the first episode, he retaliates against an employee who's embarrassed him in front of his superiors by firing her on a pretext, reducing her to tears before claiming it was all a joke. But it's Brent's artistic frustrations that give the character depth. It's good for a laugh when he whips out his guitar at a management training session, but underneath is the rancid frustration of a man who never became what he thought he'd be, and can't admit it. Such illusions are, in fact, what all of The Office's characters have in common: Tim (Martin Freeman), the 30-year-old college dropout who keeps saying he'll go back to school; Gareth (Mackenzie Crook), the power-grubbing toady who thinks he's a heartbeat away from running the show; even Dawn (Lucy Davis), who clings to the belief that her callous lout of a fiance is the right man for her, and not her obvious soulmate, Tim. The supremely self-ignorant Brent may be the butt of The Office's bluntest jokes, but Gervais makes it impossible to dismiss him as a mere buffoon. The show's six-episode first season is a perfect, self-contained work, so much so that adding onto it seemed practically sacrilegious. But if the second season splits comedy and tragedy too neatly (at its best, the show is both at once) and makes Brent too much of a victim, the final two episodes restore the balance. The Office's mock-documentary concept has never been more than a convenient ruse, but for the final two episodes, it's allowed that the first two seasons have finally aired, turning Brent into a reality-TV star, as close to real fame as he'll ever get. It's a conceptual masterstroke, and it proves that the heart of the character has always been his not-so-hidden lust for fame -- which, oddly enough, is what finally redeems him.

My Darling Clementine ($19.98 DVD) Considering that it offers a near-complete version of John Ford's classic Western before Darryl Zanuck recut and reshot it without Ford's input, you'd expect more ballyhoo surrounding Fox's elaborately endowed DVD. But the understated approach is somehow appropriate for Ford's laconic tale. Though it climaxes with the shootout at the OK Corral, Clementine almost treats the famed gunfight as a pretext; Ford is far more interested in the texture of everyday life, the petty brawls and minor allegiances of frontier life. (Peter Fonda recalls how his dad described it as the "art film" Ford smuggled into the studio system.) Henry Fonda's Wyatt Earp is a straight shooter, especially compared to the short-tempered Doc Holliday (Victor Mature, in an undervalued performance), but he's something of a rube as well, fidgeting in the barber's chair, wincing when he's sprayed down with cologne. (In Ford's original ending, Earp merely offers Cathy Downs a fond handshake before leaving town, not the tender kiss on the cheek of the release version.) Though Zanuck's version isn't a mutilation, its amped-up emotions (what today's studio execs would call "raising the stakes") violate Ford's plainspoken tone, though the latter may, now as then, strike some as unnecessarily distant, dustily removed. Happy the DVD owner, who can flip the disc over and choose one or the other.

Misc. Picks I-House celebrates Chinese New Year with Zhang Yimou's Happy Times (Fri., 8 p.m., $6, International House). The Tin Hat Trio, whose members have played with Tom Waits and John Zorn, rounds out the week's silent-film trifecta, accompanying the pioneering stop-motion animation of Ladislaw Starewicz (Wed., 8 p.m., $15, Prince Music Theater).