"I live 30 minutes out of Boston, MA and never really notice the local accent." - iwire
I know that was an old post....
But leave the Boston area for a while, then go back, you'll notice it! Even within Boston itself I can detect differences between natives of certain areas. (N. End, C-Town, S. Boston, E. Boston, Medford, Revere, and Somerville.) I sometimes them spot them out here in CA, sometimes clear across a crowded room. When I first came out to CA, I don't know how many times I was accused of being Irish, or Scottish, until I started to loose my accent. (Which in retrospect sounded like a low frequency James Cagney.)