Feel the Wheel is a free windows application which helps you in quickly resizing any open window using your mouse wheel. Apart from this it also allows you to change the transparency of the windows if you feel like taking a look beyond that window.
After trying to for 2-3 days, I did find it little addictive because of the ease with which I can re-size it. To re-size any windows just move your mouse over the top section of windows and scroll your mouse backward or forward to decrease or increase the windows size . Download it from here