Do you sometimes need a snapshot of a program window while you're working in another program? If you do, you can easily create an Automator application to do the job for you.

Open Automator and drag "Take Screenshot" from the action column to the Workflow pane. Click the button next to "Type" and select Interactive. Next, click in the circle in front of Choose Window. Click the button next to Save to and select a location from the drop-down menu for saving the file.

take_screenshot

Drag "Open Finder Items" from the action column to the Workflow pane, under "Take Screenshot." Click the button next to Open with and select your graphics program from the drop-down menu.

open_graphics_program

Select "Save As..." from the File menu and save the workflow as an application. Locate the new file and drag the icon for it to the Dock. When you need to take a screenshot of an open window, just click on the application in the Dock. Automator will ask you to select the window for the snapshot before taking it and sending it to your graphics program.