How does a person break into usability?
This question came to me as I was reading an article recently about contract employment and I remembered a post I made to Google Groups some years back to comp.human-factors. My question came about because I had received my PhD in human-computer interaction from Cardiff University's School of Psychology. At the time, I had some professional (i.e., commercial) experience in the field, but only for short contracts. I had also applied for jobs in usability companies thinking that my qualifications would get me a "foot in the door". However, the truth was that I wasn't invited for interviews to the companies I applied for. It is difficult to get into the field though it is hard to know why.
I found that asking for feedback from the companies I applied to was a good idea. Quite often, they would highlight deficiencies in my curriculum vitae (for example, I put my professional experience under the heading "Industrial experience" and was told that I was turned down because I had no stated commercial experience).
So since then, I have completed a number of contracts of differing terms and have now formed my own usability company because it's still hard to get interviews. The hardest part for this will be marketing and advertising - making the people who make the decisions aware of the company and the work it can do.
My advice is to realise that a lot of employers don't really know what usability is. I would try to put together a number of sites into a portfolio, receives critiques and use them well, and put yourself forward as a graphic designer with usability skills. I'm quite serious - just being demonstrably proven in the field will not be enough. Anyone wanting to enter the field needs to be multi-skilled to fit into the different concepts that people have of usability and meeting these will not hurt.
Work based experience is generally seen as more important than educational (this report is interesting reading), though sometimes it is not enough for a competitive field. From my own experience in this field, I would say that qualifications are actually of little use when compared to employment (and by employment, I mean permanent work for companies rather than contracts).