>I took a look a M Theory and found it interesting, but I don't really have the physics background to understand it.

I don't either, but I like to read the popular stuff. Here's a peice by Hawking that I thought was interesting:

http://www.damtp.cam.ac.uk/strtst/dirac/hawking/
"Some people will be very disappointed if there is not an ultimate theory, that can be formulated as a finite number of principles.I used to belong to that camp, but I have changed my mind. I'm now glad that our search for understanding will never come to an end, and that we will always have the challenge of new discovery.wIthout it, we would stagnate. Goedels theorem ensured there would always be a job for mathematicians.I think M theory will do the same for physicists."

Personally, I think this is a big clue, that somewhere on the path to String Theory a wrong turn was made.

Physicists don't like to consider the possibility that they've made mistakes, though ;-)