This Slashdot post makes a ton of sense to me:
Evans takes a stab at explaining why the new guy can't code when his interviewers and HR swear that they only hire above-average/A-level/top-1% people. Evans fingers the technical interview as the culprit, saying the skills required to pass today's industry-standard software interview are not those required to be a good software developer. Instead, Evans suggests: 'Don't interview anyone who hasn't accomplished anything. Ever. Certificates and degrees are not accomplishments; I mean real-world projects with real-world users. There is no excuse for software developers who don't have a site, app, or service they can point to and say, 'I did this, all by myself!'
I think all of that helped me a lot. When I was asked about prior work, I was able to point to this blog - powered by software I wrote. I was able to point to BottomFeeder - which is largely my code (I did get a lot of help from a lot of people on that one, but it's still largely my code). I could point to my Facebook interface code (and so on, and so on). Having your own site - especially one powered by code you created - is a very easy way of saying "At least once, I did something that works". As opposed to "I received this snazzy certificate that hangs on my wall".