The high-rise at 500 N. Lake Shore Drive is the second-most expensive in the city, with rents for a one-bedroom apartment approaching $3,000 a month, well beyond the reach of most Chicago residents. But that's not too much for the Chicago Housing Authority, which has used federal tax dollars to pick up most of the tab for four lucky residents in the year-old building, with its sweeping views of Lake Michigan, a concierge and a dog-grooming center. The tenants moved in over the past two years as part of a push by the CHA to expand its housing voucher program...