About WindowClipMBI
A Mac menu bar application for creating clipboard snapshots of the windows on your Mac in any application, for any application, and more. Features include: scaling, composite, trimmed composites, filter effects, timed shots. Using its special features WindowClipMBI can create screenshots not possible (or not as easily) with other methods.

To use: Install and run the application. Click on the menu bar icon for WindowClipMBI to display its menu. The menu shows the windows currently displayed by your Mac. Make a menu selection corresponding to the window you want to take a snapshot of. The image of the window is put on the clipboard, signaled by the harp sound. Many more features.

Read more: http://www.apple.com/downloads/macosx/imaging_3d/windowclipmbi.html