I've seen quite a few posts telling the OP to apply to the big companies such as Google, Microsoft, IBM, Cisco, etc.....
It could be worth a shot to do this. However, now you are now competing with a large pool of very qualified applicants who may have conducted research in the specific areas that the job is in. The odds of landing a position at a big Tech company may be slim with a PhD in a research area outside of the companies interest area.
Although the PhD, your research, and your experience could add significant value to the company, it may be difficult for prospective employers to see/appreciate this value. Like other posters have said, consider starting at the bottom (volunteer, low paying position, startup, self-employed)
Heck, one of the greatest physicist of all time, Albert Einstein, spent 9 years after he graduated trying to get the job that he actually wanted. Four of those years were after he had written four papers in 1905 that would revolutionize physics. During the interim period between graduating and landing a professorship, he took a tutoring job, worked as a patent clerk, and taught classes pro-bono at a local university.