Hmm, people. Listen up.
The problem is not, at least according to the guy asking, that he's ashamed of his apperence. The problem is that he feels ashamed of entering the online dating scene. Now, this IS a problem.
I've posted online profiles at different websites getting ZERO responses without pictures(During the first days, or week, when the staff are 'accepting' the picture), and then immidiately having girls writting to me once the picture(s) are there.
This is a fact.
Now, to the most important point. Do not believe that someone will write you and ask for a picture unless your personal profile is outstanding(Even then the odds will be against you).
Why is this? People are lazy!!! Just put yourself in their situation. There are thousands of guys on the dating site, and almost all have pictures. Why in the whole world would this girl take her time to first write you a email, motivate why she wants the picture, wait for hours and even days to recieve the picture -- When she knows that you might - not even - be good-looking?(from her point of view... which is the only one that really matters in this case).
This girl knows that she, instead, could spend this time finding at least 10 other guys which she ALREADY KNOWS are good looking.
Just think about it. This is how I do when browsing communities like myspace or dating sites for good-looking girls.
If I see a girl without a picture(which have been a member for a while) I think;
"Oh, if she doesn't have a picture im sure she's ashamed of herself. NEXT!"
As a matter of fact I don't even read the personal description. The first thing I do is looking at the picture and trying to decide weather I wanna get to know her or not.
Girls work the same way.
You do as you like, but just remember - The odds are clearly against you without a picture. It's up to you.