Is It Appropriate To Call Hiring Managers Directly When Cold Calling For A Job Search?

My wife and I are soon moving to Nashville and I was wondering if it was appropriate to call hiring managers about your skills and skill sets directly and leave them messages? I know this is what head hunters do for candidates, as I use to work for a temporary agency that placed permanent hires.
Would it be better to call during the week or on the weekends? I am currently working, so calling during the week may be a bit challenging. I kind of got my current position this way, though I knew people in town so it was easier to do. I actually called HR and left them a message. I was called back immediately and the VP Controller “thanked” the HR lady for bringing me to him. However, I am applying online right now and am not having much luck, other than one company flying me in to interview only to send me a “form” rejection e-mail.
Please advise.

Who Do I Address A Good Cover Letter To When I Don’t Know The Hr Directors Or Hiring Managers Name?

I’m applying for a job and writing a cover letter, but I’m unable to get the name of the person that is in charge of the hiring/interview process. I know it’s always best to get this persons name so you can write a more personable letter, but I can’t find it and I don’t want to address it to “whom is may concern”.
Thanks!

Is It Bad To Address A Cover Letter “dear Hiring Manager”…?

I’m applying for a job at a hospital, and I can’t find the name of the human-resources manager or director of the department anywhere on the website. Is it okay to address my cover to noone in particular?