Charmingly sweet and literate, this sexual comedy of errors provides a far less forced J.D. Salinger update than the previous year's wildly praised The Royal Tenenbaums. With its muted digital-video palette and tasteful Upper West Side environs, Gary Winick's cinematic universe is as familiar as a Woody Allen classic. But the script, by Niels Mueller and Heather McGowan, proves equally at home in the poetry-steeped libido of a precocious teen as it does in the quiet contentment of finely appointed professionals. Sigourney Weaver buttons down, inhabiting a more thoughtful, less brittle variation on the upper middle-class matron she played so convincingly in Ang Lee's The Ice Storm. John Ritter, meanwhile, continues his impressive string of character roles as the frumpy professor whose son rightly sees through his hollow domestic routine. In the title role, Aaron Stanford is a revelation, needy but grave and dignified, the gears turning almost invisibly behind his hungry eyes. But it's Bebe Neuwirth's wicked cackle and Broadway-honed comic acuity that give the film its friction and its warm sense of abandon. These characters live in a carefully circumscribed world of rent control and the right wine, but Neuwirth's vitality breaks through the exteriors and into the heart of the matter -- the crackle of longing that accumulates like static electricity and sometimes discharges at the wrong place and time. It's almost ridiculous to single out yet another performance after praising all of the principals, but Robert Iler shines, too, as Oscar's common-sensical comic foil. From its cast to its cinematography to its finely honed dialogue, Tadpole gets every little detail right.