Ellipse Select Tool
S three times
Create elliptical or circular selections with this tool. Click, hold and drag to create a selection.
The initial click point defines one corner of the selections bounding rectangle. When the pointer is moved, the selection is resized with the opposite corner of the bounding rectangle matching the current pointer location.
Force an elliptical selection to remain round by holding down the
For more information on making selections, deselecting active selections and the five selection modes see the Selection Tools page.