Ask HN: Which YC startups have launched before joining YC?

I know COLOURlovers had been around for a while before joining YC. Airbnb did a re-launch after joining but had been around perviously as well.

As far as I know rapportive also already launched. They did just write a blog post on that: http://martin.kleppmann.com/2010/12/21/having-a-launched-pro...

Hipster (http://usehipster.com) is one.