Chrome Incognito Mode

from google:
"For times when you want to browse in stealth mode, for example, to plan surprises like gifts or birthdays, Google Chrome offers the incognito browsing mode. Webpages that you open and files downloaded while you are incognito won't be logged in your browsing and download histories; all new cookies are deleted after you close the incognito window. You can browse normally and in incognito mode at the same time by using separate windows.
Browsing in incognito mode only keeps Google Chrome from storing information about the websites you've visited. The websites you visit may still have records of your visit. Any files saved to your computer will still remain on your computer."
Hence it an option to maintain privacy..the same feature is included in IE8(beta)
Hope it helps!