From Bantam Bit Software:
HideWindowPlus lets you instantly hide any Window off your screen with a single keystroke or right click on the Close button. Plus this utility allows you to quickly run a screensaver, turn off monitor or mute sound using hotkeys. Program runs invisibly in background and doesn't clutter your system tray. Hide Window Plus can hide single windows as well as several programs at once. Single windows can be hidden by right-clicking the Close button, as well as with customizable keyboard shortcut. Programs to be hidden should be added into the Hide Programs list and are hidden with keyboard shortcut. Hide Window Plus itself runs invisibly in the background and doesn't create any icons in the system tray and can be installed in "stealth mode", without creating any icons in the Start Menu.