in reply to Web-based certification services
I don't believe in certification.
I don't think that programming is something you can measure through a test. At least not the kind of test on-line companies offer.
Does anybody apart clueless HR departments still believe in MSCE's for example?
Talking to someone about a language, why they like it (or not), asking to see a piece of code they have written, then asking them to write a couple of short scripts, with and without common modules, that should be enough to evaluate a candidate. And if they don't know the language but know a couple of related ones (in the case of Perl C, sed/awk/sh would be the best background) don't worry, learning a new language is not that difficult.
But trusting an on-line certification to evaluate whether a candidate will be a good programmer? Yeah right!