If the DVDs, USB sticks, phones, cameras or any other media and devices are automatically starting to play or open explorer windows and your don't want them to, this is how you tweak the AutoPlay settings.
Neat little trick to force the preview images of running programs in Windows 7 taskbar or a so called Aero Peek, to show instantly with no delay at all.
Windows 7 have a nifty feature which combines the windows of opened applications under the same taskbar button. If you don't like it you can always turn it off.