[ghaff]

I think some of the divergence of opinion here is that a lot of people have primarily experienced filling out a form on a website--in which case a cover letter is pretty divorced from it's original purpose of going in an envelope with a resume.

On the other hand, an email to someone you know may be more important than your resume. For one job, I'm not sure if they ever ended up with my resume at all unless the business office wanted it for some pro-forma reason.