Was having this OmniAuth & Facebook: SSL certificate verify error on my Windows machine. It says
SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed. And everything is working fine on my Mac, so I got kinda annoyed when the mentioned hacks and workarounds in http://stackoverflow.com/questions/3977303/omniauth-facebook-certificate-verify-failed/5512518#5512518 are not working.
In the end, this is what solved it. https://gist.github.com/867550