MILEY CYRUS has finally gone totally topless.  If the image that popped up on the web yesterday is legit . . . and it seems to be.

It's a black-and-white outtake from her recent "W" magazine shoot, and she's lying on a bed with her breasts FULLY EXPOSED(WARNING!  Much nippliciousness awaits you.)

Meanwhile . . . Miley has quit smoking.  The LEGAL stuff, anyway.  Earlier this week she Tweeted, quote, "2 months no cigs.  #proudofmyself"