The Corcoran Group recently released their quarterly market report covering closed apartment sales (condos and coops) in Brooklyn for Q1 2011.
PropertyShark has put together an interactive map showing the sales that closed and were recorded in the first quarter of 2011. The size of the circle indicates the number of sales in the building and the color indicates the price per square foot.
On the map, you can click on a building for a mini-report pop-up displaying details about sold units in that building.

Click on the following link to browse current Brooklyn apartments for sale.