In Mac OS X 10.4 Tiger, Safari 2.0 has new keyboard shortcuts for selecting tabs. The new keyboard shortcut for Select Next Tab is Command-Shift-right bracket (]). The shortcut for Select Previous Tab is Command-Shift-left bracket ([).
Note: Because Shift-] results in }, you may also see this key combination abbreviated to the form "Command-}", as it appears in the Window menu in Safari.
The original combinations, Command-Shift-left arrow (←) and Command-Shift-right arrow (→), still work except in these two situations: Your keyboard focus is in a text field, or you switch to a blank tab. Be sure to use the new method in these situations.