Now you are into the EXPOSE and SPACES settings. When you look at my settings, you will see that I have asked for ALL WINDOWS to appear when I go to the bottom left corner of my screen and if I go to the bottom right corner of my screen, I will start my Screen Saver.
You choose what you want to happen at the corners. Have one corner show ALL WINDOWS. Close SYSTEM PREFERENCES and move to the corner you chose.
You should then see a screen that looks like this, showing all open programs and windows.
You can see all my windows and you will notice when I rolled over a window with my mouse, it shows me its name.
Just click on the window you want!