I can't speak to the quality, but there are such services. If you Google "online counseling" or "online psychiatrist" you will get a ton of results. Most are not free, and again, how much help the person can be without physically talking with you is open to question.

Here's one that has general "counselors" : http://www.asktheinternettherapist.com/

And here's one that has specifically psychiatrists:
http://www.liveperson.com/experts/he...ne/psychiatry/