The best place to ask for a personal referral in any US cities, in a non-emergency situation, imho is city-data.com
I don't have a problem when traveling in the US. I just called my VISA and they referred me to 2 - 3 doctors nearest to my location.
edit: same day appointment guaranteed and even immediate bedside attendance possible
A neighbor experienced pain in one ear, and his doctor's appointment was 2 days later. After he bought and administered the prescribed ear-drops, the same day within an hour or so, he started to have rashes and weird pimples on his facial skin. He called back the doctor's clinic, and the medical receptionist told him that since he had just seen the doctor, she could squeeze him in earliest the following week, i.e. in 2 days later.
That night his pimples were oozing liquid and he was in great pain, and since he has no car we drove him to the ER. Even then it was too late as treatment must be within 72 hours. Thus if Massoumi's idea of booking doctor's appointment online can get around officious medical receptionist ...... but I doubt this will work out where universal healthcare is practised.