One employee at the Apple Store in the Galleria is a shaggy-haired slacker who stumbles around the place singing to himself. "Hey, what's up?" he'll interrupt himself to ask a customer. "What's the deal-i-o?" The store, painted stark white with blond wood floors, is as sleek as the wafer-thin iPods on display. It has fast replaced the arcade and record shop as the spot in the mall where hipsters go to hang. And why not? The place hums with activity as teens download songs and videos, check their MySpace pages and surf the Net. The little ones have a station all their own, where they play Dora the Explorer and Nemo. An older crowd occasionally wanders in as well, gazing lustily at the powerful Mac G5 and the giant 30-inch monitor on display. And all day long, people of every age hunch over counters, legs crossed at the ankles, looking as laid-back as the employees.