For example, if you are using IE, when you press alt + s, the focus is moved to the Scrapbook link at the top of the page. Pressing enter will then take you to your scrapbook page.

On Netscape Navigator and Mozilla Firefox,  alt + shift + s should take you directly to your scrapbook (you don’t need to press “enter”). Similarly, if you hold down  alt+shift,  simply press h for home, p for profile, b for friends, c for communities, l for logout.

Actually this accesskeys designed for visually impaired users, it can be difficult to navigate through orkut using a mouse to point and click on various links for them. In order to make orkut more accessible to all users this accesskeys are made.