Evidently, the conference board has some measure of online job advertisements, available (I think) for only since 2005 or so. My RA reports that they want $20K for the data. Uh...sure. I'll see what I can do about this.
But in the meantime, I provide plots of regional Beveridge curves using JOLTS data which, unfortunately, is available only for the past decade. I do this first the conventional way, plotting vacancies against unemployment. But because I am no fan of unemployment measures (half of the flow into employment comes from out of the labor force), I also plot the BC my preferred way; that is, with vacancies plotted against the employment ratio.