I'm not a fan of freenhand capture -- to me i think it is far better to capture the entire screen and then select and crop WITHIN the program (rather than at time of capture), because doing so after the capture allows you to undo, zoom, etc.
Screenshot captor has tools in the interface for freehand and magic lasso selection/cropping.
My suggestion to people who want freehand capturing is to break yourselves of the habit of wanting to so precisely control the selection at time of capture, and go for a 2-step capture then crop.