The hottest fight in advertising is about credit-report Web sites.

The Spot: A guy plays guitar in an Irish-themed bar. He's accompanied by a drummer and a bassist. All three wear kilts. "AnnualCreditReport.com," the guy sings, "the one you can depend upon." He goes on to describe the hazards of signing up with other credit-monitoring Web sites: "Beware of the others. There's always a catch./ They claim to be free, but strings are attached./ Their ads can be funny, so don't be deceived./ Hold onto your money. There's one site you need."

Do-gooder public-service announcements have long been a part of the advertising landscape. PSAs are often mockably earnest and dorky, but they can serve a useful purpose by alerting you to important information. Consider this piece Ad Report Card's contribution to the PSA genre. I'm donating this valuable space to spread the word about AnnualCreditReport.com—a wonderfully useful Web site that's currently being promoted by a pair of videos produced by the Federal Trade Commission.

You've no doubt seen the TV ads for a different credit-check site, called FreeCreditReport.com. Those ones where a sunny-faced, curly-haired dude sings narrative pop songs about the calamities he's endured as a result of his poor credit. This unfortunate fellow is reduced to working in a tacky, pirate-themed restaurant because "some hacker stole my ID"; buying a subcompact jalopy because his "credit was wack"; and living in a basement because of his wife's previous default on a credit card.

These ads have warm, vibrant visuals. (They're directed by Danny Leiner, who's helmed similarly low-key, goofball comedies like Dude, Where's My Car? and Harold & Kumar Go to White Castle.) They feature an appealing slacker protagonist. But above all, they benefit from a slew of maddeningly catchy songs, executed in a wide variety of genres.