If you cast a Christopher Guest mockumentary from real life, played it absolutely straight, and eliminated all ridicule and absurdity, this warm-hearted doc about supermarket baggers might result. Working with the evident cooperation of the National Grocers Association, which sponsors an annual competition in Las Vegas, filmmakers Alex da Silva and Justine Jacob profile eight qualifiers from around the country. All of them are nice; their families are nice; their employers are nice (no sign of Wal-Mart); and the film is tremendously nice to them. But after about 20 minutes, you begin to wish for some tension beyond bruised fruit and burst plastic bags. (The five finalists compete in both paper and plastic categories.) Yet nobody comes out of the closet or admits to a drug problem, no one's marriage falls apart, and you're left with cheerful, decent people frantically juggling canned corn and cereal boxes. Which, depending where you shop, is a routine experience—though not everyone's so happy to be bagging at the neighborhood Safeway. Three of the eight contestants here are past 40, and you wonder if this is what they expected to do with their lives. The polite filmmakers never ask, nor do they mention anyone's hourly wage. When the final bag is filled, the contest winner calls it "one of the greatest moments of my life." Ready, Set, Bag! grants him the dignity he deserves, but a postscript indicates a brighter future for a teenage finalist in our stratified economy—he's studying engineering in college.