A few months ago I had a post about a certain accent or dialect  that I have noticed around New York City.  Here is an excerpt:

I know one thing that confounds me is the hard O.  For instance the O sound in Tom or com.  It sounds like it comes from way back in the throat.  Not quite British and not quite New England.  If any of you listen to WNYC there is a woman who does the promos and she speaks this way.  It's the way that I imagine a Vassar or Barnard grad speaks.  "You're listening to WNYC dot cahhm."    

   Then there is "Thank you so much" (I hate that expression)   That comes out sounding "Think you so much."   And the general elongating of the vowels leading to that valley-girl sound.  Towtally.  

   I realize I'm probably talking about more than one accent here.  The valley girl accent -- oh muh god!!! --  is different than that preppy way of pronouncing the hard Os.  Emyn commented on the valley girl portion of my post:

  Emyn: I know how that sound. It's like, ya know, towtally immachurr. With a tone that's, like, tilting at the uhnd of uhvry sentuhns. It's, like, so awfuuuuhhhlll!

   She is dead on in her assessment.  But for now I am obsessed with the 'preppy' accent.  I even catch myself doing it.  Is it Northeast regional?  I was even thinking it could be a Manhattan thing -- they don't have the hardcore New Yawk accent in Manhattan.  That's more a Brooklyn/Queens/Bronx/Long Island trait.  I just want to know where this originates from.  Is it something that has always existed and I never noticed until now -- or is it a recent phenomenon?