I'm with ya - I hate writing cover letters. I just love the websites that say "Enter your cover letter here (optional)" - Who are they trying to kid that it's optional??
Here's what I did for mine:
Paragraph 1 specifies the job I'm applying for and says I'm a great candidate.
Paragraph 2 is my background, education, and experience.
Paragraph 3 is customized to the company and indicates why I'd be a good fit. (This shows them I've researched the company.)
Paragraph 4 gives my phone and email and thanks them.
HTH, and good luck