During October 2012 you can get Hide Any Window
4.0 for 9.95USD instead of 29.95USD.
Hide Open Windows
Hide Any Window helps you escape clutter on your desktop - you can select to close or minimize windows and programs, hide programs automatically whenever they are started, so nobody knows you are using these programs and windows at all.
You can easily hide open windows, running programs and games
Automatically show windows and programs you are supposed to work with
Hide windows and running applications from the desktop, hide running programs from Taskbar and Task Manager
Hide programs' icons - aka tray icons from the system tray
Hide windows and programs automatically whenever they are opened or started
Simply restore hidden windows by hotkey (boss key)
Minimize all windows by hotkey - hide windows minimize option
Close browsers by hotkey (bosskey)
Customizable hotkey combinations
Mute sound in hidden applications
'Start with Windows' option