Do Cover Letters Really Matter?

As part of the ongoing job search I'm constantly debating the effectiveness of a cover letter.

Having been in a supervisory position in the past I can say that most cover letters bored the hell out of me. They say the same thing over and over and over and add nothing to my impression of an applicant unless the grammar and spelling is so bad that you wonder if the applicant is 14 years old. Honestly, they never factored in my decision to call someone in for an interview. I looked for skills and qualifications, items easily seen on a resume.

I think the biggest arguement for cover letters comes from HR professionals who seem to think it is the Holy Grail of a job application. Just do a quick google search and you will find many blogs by HR professionals who say the cover letter is what sells the employer on interviewing you. Yet these same people say in the same post that cover letters are pretty much the same from all applicants. I even found one entry where a professional stated he doubted even a fast food restaurant would hire someone without a cover letter.

I realize that the HR department is a companies first line of defense in the legalities of running a business. I've never bought the stand that the HR department is for the employees. I do understand that they scan the resumes and provide a sampling of what they think are the most qualified candidates to the hiring supervisors and managers of the appropriate departments. The problem is they often have no idea of what a job involves other than what is in the manual as a job description.

So, the dilemma is...conform and write a cover letter that says "Hi, I'm the most qualified! Hire me!" or just add a note of interest to an email?