Preview all tabs with Safari in Mountain Lion
In past versions of Safari, you had to navigate to a new tab to view its contents; however, with Safari 6 in Mountain Lion, Apple has added a new feature that allows you to preview all of the open tabs in a window.
When you create tabs in the browser either by clicking the plus button to the right of the toolbar or by pressing Command-T, you will now see a button appear next to the plus that looks like a small rectangle with margins. Clicking this (or selecting "Show All Tabs" in the View menu) will shrink … Read more