In addition to setting the center of a view's frame, now you can query it.

AppKit/CPView.j

@@ -573,6 +573,15 @@ var DOMElementPrototype         = nil,
     [self setFrameOrigin:CGPointMake(aPoint.x - _frame.size.width / 2.0, aPoint.y - _frame.size.height / 2.0)]; 
 }
 
+/*!
+    Returns the center of the receiver's frame to the provided point. The point is defined in the superview's coordinate system. 
+    @return CGPoint the center point of the receiver's frame
+*/
+- (void)center
+{
+    return CGPointMake(_frame.size.width / 2.0 + _frame.origin.x, _frame.size.height / 2.0 + _frame.origin.y);
+}
+
 /*!
     Sets the receiver's frame origin to the provided point. The point is defined in the superview's coordinate system. 
     The method posts a CPViewFrameDidChangeNotification to the default notification center if the receiver