Old-Fashioned Play--For Pay        Kids !Come have a ball! Or 60,000 of them! There's a new type of business franchise that is appearing in shopping malls and neighborhoods acrossprefix = st1 /Americaoffering pay-per-use indoor playgrounds ,which feature toys ,games ,supervised fun and a workout that doesn't break the family bank.        As public playgrounds grow increasingly worn and dirty, the for-profit centers offer clean, safe supervised activity as well as a variety of challenging exercises to develop youngsters' physical fitness, usually for a fee of around 5$ an hour. "Playgrounds are dirty ,not supervised," says Dick Guggenheimer ,owner of the two-month-old Discovery Zone in Yonkers, N.Y., part of Kansas City-based chain, "We are indoors; we are padded ;parents can feel their child is safe".        In order to satisfy the need of two-earner families ,the new franchise stayed open in the evenings ,long after traditional public playgrounds have grown dark and unusable .However these new playgrounds are not meant to be day-care centers .Parents are expected go stay and play with their kids rather than drop them off. But several also provide high-tech baby-sitting services. At some of the Discovery Zones, parents can register their children in special supervised programs, then leave them and slip away for a couple of hours to enjoy a movie or dinner. If there is a problem ,Mom and Dad are called.        The most fun of all, though, is getting to do what parents used to do in the days before two-earner families and two-hour commutes; play with their kids. That ,at least ,is old-fashioned, even at per-hour rates. What is this article mainly talking about?
The fast development of Discovery Zone. The disadvantages of outdoor playgrounds. A new type of business franchise for kids. Children can play in the public playgrounds without parents' care.