If I put on my resume that I'm HTML, JavaScript, and PHP (although I haven't gotten PHP yet) certified, how do they then confirm that? They obviously have to, unless they take you at face value.

Do they ask for verification numbers and the company I got it from, and then check it out?

Also, how credible are online certifications? Will I be laughed at if I say "I got certified through BrainBench" rather than a traditional testing facility?