It's our favorite time of year—the time that barricades and fences line Fifth Avenue up by Central Park, when Upper East Side shopkeepers board their windows. It's the Puerto Rican Day Parade this coming Sunday! (And it's too bad Arthur Carter no longer owns the Observer—his editorials about what he could actually see from his Fifth Ave. apartment windows were priceless; enjoy "Puerto Rican Day Parade: Filth and Garbage.") This year, says a recent park-goer, the fences have been up for weeks along the park side, conveniently in place since the AIDS walk. According to what he heard a Central Park Conservancy staff member saying to a dog-walker, they'd actually put the fences up to make sure all those scary Ricans can't blast their boomboxes and litter their tostones in the sacred fields of ultimate frisbee. Well good for them!