There is one feature in Windows 7 that I though was useless. Basically, you take title-bar of any window and move mouse (shake it) while holding left mouse button. That action causes all windows to disappear thus leaving your window as single occupant of desktop space.
Today I wanted to copy one file to desktop. I had mouse in my hand but also a lot of windows in path between explorer and desktop. There was no easy way to see desktop except minimizing all windows except one with my file. Than I understood.
This shake it motion is for people so lazy that one additional minimize all would be troublesome. That said, I did like it. :)