A good approach to this is something that I would call "passive targeted recruiting", basically implement policies as "always be recruiting" and having your doors open (office-hours work great for this), take 1 - 2 hours of your week to talk with people interested in knowing more about your company, etc. Also I would say enforce cultural fit over technical, I saw Polyvore's about page and see that you do a really good job selling your culture :).
We release recently an interview with Daniel Doubrovkine about office-hours http://bit.ly/WFhVvo, he also writes a lot in his blog about hiring http://code.dblock.org/help-me-fix-tech-recruiting-become-a-...
Hope it helps! I would be interested in discussing further about the subject if you want (email is in my profile).