Thanks Nereid and Tensor for giving some names involved in string theory. By the looks off what I read in several reviews about their publishing, I'm convinced I'm not quite ready to comment them.
If there is no way of verifying those theories, then indeed, it's not easy to accept it as a science. I do not longer expect to read any understandable overview of string theory either.
But it is still a good thing there are many efforts to keep searching.

By the way, is there any way of telling how string theory started ? Has it been pure theoretically, or has there once something happened or occured, that triggered the need for such strange thoughts ?