[ghshephard]

You can either:

   CMD+Left Click
   Right Click + "Open Link in new Tab"

[Gmo]

I'm sorry but that doesn't do the trick.

The right click + Open link takes way longer than a middle click.

The Cmd + Left click, while being closer to a middle click, still forces you to move your hand to the command button.

[Hoff]

When you're writing documentation or designing UIs, please remember that the right and left references for the mouse buttons are entirely ambiguous.

Most mice have been configurably-ambidextrous for a decade or more, after all.

The X Windows folks got this one right very early on with their configurability and their use of MB1, MB2, MB3 notation for the mouse buttons.

[der_ketzer]

Or mouse gestures in Firefox.