McDonald's Corp. launched the fast-food business with a limited menu and take-out-only service. Then menus became fatter, restaurants fancier, and prices higher. Now, Hooker Enterprises Inc., of Nashville, sees a promising niche in turning back the clock to recreate the original fast-food concept. Its no-frills, take-out-only menu and prefab decor are designed to undercut competitors' prices. The company, whose first Hooker's Hamburgers unit opened in December, plans to franchise.

Video pirates fleece the movie business of an estimated $1 billion a year. So Macrovision, of San Jose, Calif., developed a way to encode tapes or television broadcasts so that copies made on a videocassette recorder end up with wiggly lines, distorted colors, and other annoying features. The Macrovision process costs from 15? to $2 per cassette. The first cassette in which it is used, The Cotton Club, hit the market in April.

The wooden fence business is booming, thanks in part to zoning laws that forbid chain-link fences and to consumers who crave privacy. But wooden fence posts are likely to rot. After years of hearing consumers complain, Ben Bewley developed a substitute: steel posts coated with polyester and colored to match the wood favored by today's suburbanites. Since Durapost Support Systems Inc., of Germantown, Tenn., opened in January, it has expanded its sales to 15 states.

When banks began to emboss three-dimensional images on credit cards, they introduced holography to the public. Jim McNulty, a holography artist, saw an opportunity. Now his Holography Center Inc., of Clifton Heights, Pa., creates images for packaging, trade shows, and restaurant decorations. It expects sales of $2.5 million in 1985, and is designing such massmarket items as holographic wrapping paper.

Stiffer drunk-driving penalties have been a boon to Doug Pender, an admitted "happy-hour stopper." Drivers Inc., of North Kansas City, Mo., bails people out from too much boozing by driving them and their cars to and from bars and parties. Pender's firm also offers chauffeured Lincolns, mostly to corporate clients worried about liability for accidents after company bashes.