Apple has a snuck a feature into its forthcoming OS X Lion release that permits to reboot their system into Safari, using of small page from Chrome OS of Google.
When you choose to restart your system into Safari, you are efficiently putting the Web browser into a sandbox. When it boots, your system will provide some users with physical access to your machine the skill to surf the Web. Users would not be capable to access the files of the system or applications.
Users that hit their systems in Safari-only mode will be capable to . . . → Read More: Apple OS X Lion Users Could Reboot to Safari