I am currently reading a book by Lee Smolin called The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next. I am nearly done with it and feel confident in recommending it to anyone with an interest in the problems presently facing theoretical physicists or anyone with a more general interest in the philosophy of science.
He raises a number of intriguing questions concerning what qualifies as a theory and about theory acceptance. Additionally he delves into what it means to do science and specifically how certain current theoretical avenues are threatening to impinge on the claims to truth that science as traditionally held. All of this is accomplished within a framework of a host of interrelated concepts, conjectures, and theoretical candidates now under scrutiny in physics, especially particle physics.
I found the reading material quite accessible and would guess that most readers who have come this far through my review would be able to manage the concepts under discussion. Having a backgroud in physics (even having taken a class in college) would be useful in terms of managing the vocabulary, but again I don’t think this is required to get through and to enjoy the material presented.
On a related note, he includes a citation for a seminar which took place in Canada’s Perimiter Institute a few years back. Happily there are audio recordings of this seminar available through their site (the audio page is here). Again, excellent brain yum-yums for the philosophical minded. The seminar concerns whether the physical laws are fixed or whether they might change over time (so, has the gravitational constant been constant always?).
In short, read the book; listen to the seminar recordings; think and talk like a philosopher of science (so I don’t feel so awkward at parties).