Running multiple applications simultaneously, no doubt, slows down the system but also clutters the taskbar. So if you have a habit of keeping the taskbar clean and tidy then you can make the applications minimize directly to the desktop and not to the taskbar as usually is.
The tool is called miniMIZE and what it does is, it catches the windows of the applications that are being minimized and puts a small thumbnail of it on the desktop. Thereby it makes your desktop into use and doesn’t clutter up your taskbar.
It also has hotkeys to cycle thumbnail levels, minimize all windows and show/hide thumbnails. The tool is quite small and is in beta stage and this is the reason why it works only on Windows XP at present.