In "Draw" mode: hold Ctrl key and click on map to draw a polygon, dbl-click to finish and identify all features within the polygon;
In "Select" mode: select an existing feature on map and dbl-click to identify all features intersect that existing feature;
Click "Draw Mode (click to toggle)" to toggle mode;
See Firebug console for full list of identify results;
Click "Clean up" to clean up identify results.