For most of us, embarrassing personal moments and ill-advised decisions are relegated to the trash heap of memory, mercifully forgotten by all but ourselves, and a select unfortunate few who happened to be along for the ride. Or, if you're Jeff Goldblum, you make a movie, preserving the debacle for posterity.

That movie is Pittsburgh, a very funny, sometimes painful documentary(ish) record of Goldblum's 2004 decision to quit Hollywood for a few months and join his fiance Catherine Wreford on stage in a production of The Music Man in his hometown of Pittsburgh, Pennsylvania. Recording the process from start to finish, beginning with Goldblum's presentation of the idea to his friends and thoroughly disapproving agent, and ending with the show's triumphant opening night, the film serves a dual purpose. First, it is a way of (publicly) preserving for Goldblum a strange few months of his life. Second, it gives him a chance to experiment with the documentary form, and to play with the always-mediated version of reality that such films present. In Pittsburgh, Goldblum and Wreford share the screen with Goldblum's friends Ed Begley Jr. and Illeana Douglas, along with Douglas' "boyfriend," the musician Moby; all three are presented as exaggerated versions of themselves. Begley, for example, plays off of his Environmental Crusader persona, pressuring Goldblum into helping him market a personal solar-power device (the Solarman 2000) in exchange for his agreement to appear in The Music Man. Douglas, meanwhile, is "dating" Moby, a morose, disrespectful (he's never seen any of Douglas' films) musician who also happens to be a porn hound, something he shameless discusses with Goldblum while the three are engaged in a Music Man sing-a-long. When the inevitable breakup finally comes, it takes place on camera, surrounded by strangers in outrageous costumes, as Moby leads Coney Island's annual Mermaid Parade.

What's wonderful about the movie and its celebrity "characters" is that, even at its extreme, it remains plausible. While it seems unlikely that Begley would trick Goldblum into appearing in infomercials and subject him to possible financial liability, all in the name of environmentally-friendly power, his passion for the subject makes the audience unable to completely dismiss the possibility (until, that is, we get home and conduct a "Powerman 2000" Google search). Begley and the others dive eagerly into the improvisational elements of the film, gleefully sending up their own personae, and tweaking their reputations. Begley's first appearance on screen, waxing rhapsodic about his new recycled milk carton fencing, is particularly inspired in its knowing conformity to the public expectation of what it might be like to visit Ed Begley, Jr. at home.

Though his film is, essentially, little more than vanity project, Goldblum nevertheless mocks himself just as readily as he does those around him. From frequent, cringe-inducing rehearsal scenes to incredibly harsh ("I am crazy about you, and at one point I was thinking, 'I'm gonna shoot him.'") criticism from The Music Man's director; from his friends' judgments about a fiance less than half his age to a talking-to from a stern Conan O'Brien, he freely allows himself to look foolish. Whether the situations are real (the conversations with the director, for example, are self-conscious, but also legitimate) or fictional (the exchange with O'Brien is obviously planned), Goldblum is as vulnerable as everyone else on screen, showing what must be the least ego ever on display in a movie star' vanity project.

Though Pittsburgh is of very little significance when compared to the myriad of well-made, socially relevant documentaries that are part of this year's Tribeca Festival, it's so clever, and so disarmingly free of pretense that it's almost impossible to resist. In fact, the movie features so many tiny, laugh-out-loud moments that it's small gem, and well-worth seeing for the unexpected pleasures it holds in store.