From Thyant Software:
Window Pinner utility allows you to "pin" a window to the top of all other windows. When the program is running an icon appears in the Taskbar Notification Area, next to the time display in the lower right corner of the screen. By clicking the icon, a menu appears where all currently open windows are listed. Click the window you would like to have set as top most window (i.e. all other windows lie below this window. To remove "top most" from a window again, just select the window in the menu another time.