I'm going to assume Ice was asking what makes a person marketable if they do not get into academia. I.e., what the heck do you do to secure a job after a PH.d / Masters where you are not going into Academic Physics.
Tid Bits:
I was reading the other day what makes a mathematician employable in industry. It was from an Aerospace company. If you want I can try to dredge it up.
If you as a physicist and/or mathematician can learn industrial skills, you'll probably be more valuable than most engineers. That's bold, but it is also saying you are willing to work or take extra classes to the level of a Bachelors in one of the engineerings.
Skillz:
First thing is first. You have to know what market? Are you mechanical minded, electrical, bio-, chemical, computational, etc. You decide that, and you're half way there Ice.
Next. Go after that. I was reading on PHds.org about a "back up plan" for graduate school. Things like, what the heck happens when you don't make it. They suggest, I suggest, you do learn something further outside of your research. And learn it well enough that you can get a job in that field. It would be wise to pick something that your PH.d supports in some way.
Factoid, 70% of all PH.d's in Mathematics do not go into mathematics. I got that out of the Mathematician's Survival Guide by Krantz.
For mathematicians programming is a logical move. You can either take classes or teach yourself. The later being more difficult to do and more difficult to prove you did do.
For physicists you may have more options. You know electronics theory, but can you design circuits? It's not a simple move there. It requires effort.
Analogously, if you're an uber-pure mathematician and you know some differential geometry, then learning to use tensor calculus will definitely require some work, albeit they're very related. It is still nontrivial. For one, you might lack the physics understanding required to make heads or tails of why you would use tensor calculus.
Here's a book I used in my EE electronics course, Electronic Circuit Analysis and Design 2nd ed. by Donald A. Neamen. I suggest if you like electronics you check that out and see if you can read and do some of the problems. I think you'll find it nontrivial.
Similarly, you can take courses in the mechanical engineering department. You're good at mechanics, but getting on a cad program and designing a part will not prove to be easy unless you've given that some serious attention.
Here's the bottom line:
Academia/ Science is about publishing something novel and new that can be used to find something else novel and new - and who likes your work.
Industry is about selling what you got for a profit.
It's that simple. Say, you know how to prove the snake lemma, great. You're a genius. You're not worth as much as a double bachelors major in mathematics and computer science.
Similarly, you could say you understand all about the standard model and how to read data at the BNL accelerator, great you're a genius. A double bachelors in physics and EE is going to be worth far more than you in industry.
To finish, if you got a suspicion you're not the next Hawking, then I suggest you ignore those who "made it" and learn something serious on the side. Yes, that will take away some from your work, but in the words of the great physicist Schwartz at my school, "learn to do things good enough." I.e. striving for the 100th decimal precision when all the other equipment gives you 3 decimals is worthless, eh?
A flip side to this, is can you "use people to make money?" I.e., can you manage? You could also take courses towards a career in management.
Let me tell ya, if you do go to industry, you're going to learn that Dilbert actually does depict the average manager pretty damn accurately. To that, industry has become aware of this over the last decade or so, and they have actively sought after science types who know managers skillz too.
Best of luck.
P.S. Previous posts about being a "people person" go for every job in the world.
P.S.S. Can you read this?
私はオーエンです。日本人じゃありません。日本語です。
Knowing a foreign language is great. Knowing a difficult foreign language is even better, especially in engineering.
P.S.S.S Most people would not consider me able to speak Japanese well enough to be useful, even after a few years of studying it. Honestly, it will take 5 to 10 years to become proficient enough if you do not live in Japan. So get started now if you want to add that someday to your resume.