Ask HN: Free access to scholarly journals / papers?

I wonder what's your poison when it comes to doing some research and you need to see whether there's any recent research in certain area / on some subject?

Most of the sites I get in google search results charge either subscription fee or once-off per paper fee.

So far I managed to find these resources that list some papers for free:

    http://www.doaj.org/
    http://highwire.stanford.edu/cgi/search
    http://www.freefullpdf.com/

I'd love to hear what your favourite site when it comes to research?

Thanks!