How do you provide a cover letter with your resume?

I like the two attachment approach. It was just the way I was "raised". Including the cover letter intro in an email is just too informal. I like my emails to be short and informal. Anything more formal - such as a specifically directed cover letter - requires a formal format and greater length. Even when submitted electronically.

My email in response to the posting is short and sweet. It includes my formal work signature file (I can't do that here) at the bottom, just to tout my credibility as a serious candidate though.

Ms. Keeley:

I believe myself to be an excellent candidate for the VP of Finance position at XYZ Inc. that you recently posted on Monster.com and would like to apply for that position.

I have attached a cover letter and my resume to this email as you requested.

I'd appreciate it if you'd respond to this email to let me know that you received this email and that the attachments were in a useable format for you.

Thank you,

Name
Title
Org logo & contact information

As an aside for all of the recruiter/HR types on these boards:

If I receive no response to the email as requested, I will attempt to make contact again either through email, by telephone or in person depending on the particulars of the situation. I just want a confirmation that they've received my information and can use it to evaluate me.

If their response to my inquiry is not business like, or arrogant in the don't-call-us,-we'll-call-you attitude I make a mental note to downgrade my interest in any position at that entity unless I can confirm that the unprofessional response and attitude are an anomaly. After all, if you're treated like dirt before you're hired, you can be sure it will be worse post hire. Ask me why I know this.

I would either include a few short points in an email reply with my signature including a link to my LinkedIn profile, or reference an attached short cover letter highlighting my specific experience/expertise relative to the job posted.

Having hired hundreds of people in my career, a cover letter is rarely read and is a very unlikely determiner on who was chosen for an interview. But sometimes it is expected, even if never actually read.

I like the attachment better. Instead of two attachments though the person could scan and save as PDF the Cover letter and the Resume so you are only getting one attachment. I think it's a more professional polished method.

I agree with the comment from the anonymous person although I would embellish on why I may be a good fit for the position. Although the cover letter may not fully describe the candidate's skills and talents, the cover letter generally provides other information that you may not find in a resume, such as writing skills, reason for applying, and a voice behind the applicant. I have also found in my years of HR experience, that an applicant will not submit a cover letter even when asked to do so in the job posting. To me that applicant is either fishing, unable to follow directions or is not a fit.