Open pages in tabs instead of windows:

Ctrl-click: Opens a link in a new tab, and makes it the active tab. Opens a link in a new tab. Opens a link in a new window, and makes it the active window. Opens a link in a new window.
Ctrl-Shift-click: Opens a link in a new tab. Opens a link in a new tab, and makes it the active tab. Opens a link in a new window. Opens a link in a new window, and makes it the active window.
Ctrl-Alt-click: Opens a link in a new window, and makes it the active window. Opens a link in a new window. Opens a link in a new tab, and makes it the active tab. Opens a link in a new tab.
Ctrl-Alt-Shift-click: Opens a link in a new window. Opens a link in a new window, and makes it the active window. Opens a link in a new tab. Opens a link in a new tab, and makes it the active tab.