I think you're asking kind of a broad question and there are different ways to interpret it.
i.e.
- Should I list jobs that require a physics background?
- Those that someone with a physics background can do?
- Those someone who enjoys physics is likely to be happy in?
- What about jobs that someone with a physics background could do with a little more professional training?
That said, here are some ideas:
1. Medical physics - this requires substantial training beyond a BSc. It's just listed first because I happen to know about it.
2. Health physics - some additional training may be necessary, but may also happen on the job. These would be radiation safety officers in hospitals (radiation oncology, nuclear medicine, imaging), nuclear plants, laboratories, regulatory agencies, etc.
3. Teaching community college - generally requires a PhD.
4. Geophysics - can be entered with an undergraduate degree, but graduate degrees translate into more opportunity.
5. Professional (medicine, law, engineering, etc.) - required substantial training beyond BSc.
6. Teaching at secondary, primary or private schools - often required teaching certificate
7. Technical sales (with companies like GE, Phillips, Siemens, Varian, Mitsubishi, etc.) - I tend to know more about the larger medical-related ones, but I imagine other fields operate under similar business models where they need sales reps who are intelligent enough to answer questions beyond the level of what's printed on the company web-page.
8. Project management - I understand there are certifications in this field, but I'm not sure how standardized that is, or if anyone can walk into it.
9. Technical positions (radiation therapist, MRI technologist, x-ray technician, again I'm more familiar with the medical ones) - Some technical training beyond a BSc is required for certification, but I've seen people with physics backgrounds advance quickly once they enter these fields).
10. Entrepreneurial ventures - one factor to think about when choosing a PhD project is whether or not it has the potential to lead to something patentable.
11. Technical consulting - This is something else to potentially get out of PhD work. What if you're developing a new way of measuring some quantity that has value to the industrial world - anything related to occupational health and safety comes to mind. If a consulting company exists that performs this service, look into it.
12. Law enforcement - I wasn't sure whether to throw this in or not, and I don't mean to limit it to just this field either. You don't need a physics degree, or even a degree at all to do it. But once you're in, the physics degree, particularly an advanced one may act like an accelerant allowing you to advance to more senior positions faster. Along these lines you could also think military service, where if nothing else the degree could get you a commission. You could also think intelligence - either technical such as cryptograpy, or just getting into field work.
13. National (or international) laboratory work. This likely requires a graduate degree, although some people can find with a BSc as a laboratory assistant. What about something like working in a ballistics lab? (Okay, maybe I've got CSI on the mind tonight or something).
14. Scientific journalism or being a writer. I think this is something just about anyone can do, but very few people can do well or earn a living at. A physics background would certainly lend credibility.
15. Programming and or application development. You probably need to know more than just the five lectures in FORTRAN you took for your computational methods course, but this is also a skill that be largely developed on your own.
16. Data analysis. This is kind of a catch all. I'm thinking you can put data mining in here (hoping that I'm not inadvertently insulting anyone). Here you'd largely be capitalising on your mathematical skills.
17. Engineering. From what I've seen, it can be difficult to actually get into an engineering position without the P.Eng., but not impossible, since lots of physicists apparently do it. A lot can depend on the actual company doing the hiring and what the position actually entails.
18. Financial or economic analysis. This one comes up for discussion a fair amount around here.
Anyway, that's probably enough from me for now. I'm really only talking from personal experience on examples 1 and 2, a semester on 3, and maybe a little bit 12.