I think what Lukas was hinting at is (and feel free to correct me if I am wrong), that certifications are particulary important if you have nothing else to show.

I’m not a fan of any certification per se and because of the amount of “sillyness” which comes from people on mailinglists that boast a “X certified developer” badge in their email signature and/or blog I’d rather do the opposite.

I’m not saying that I wouldn’t hire anyone with a certification of some kind, but at the same time, with equal qualification, I’d select a candidate with OSS background.

At the very least, I’d ask anyone with a certification what they were trying to achieve there.