You'll get better results with when you've mastered good cover letters and resume cover notes. These ten cover letter tips come from someone who reads cover notes every day.
Half the resume applications I receive have no cover note. No greeting, no introduction, no summary, nada. This is the worst mistake you can make, because for many resume reviewers, it's an immediate disqualification.
Always include a brief, friendly note that says why you’re sending your resume, and offers a tidbit about your background. If you don’t care enough about the job to take a minute to write a brief note of introduction with your resume, you’re wasting your time and theirs.
It has been my experience that the majority of large corporations either use and automated program to search for key qulification words, or even outsource the initial triage application process. I think your comments regarding the cover letter may apply only to small organizations that don't process hundreds of applications. If you feel your comments regarding a cover letter do apply to large corporations as well, I feel it would be useful to include a section on how cover letters are handled by automated resume search applications, and whether cover letters are included in the processing.