The JURN site brings together humanities and social sciences articles that are made available from the Directory of Open Access Journals and the Intute: Arts & Humanities and Social Sciences websites. Additionally, the site brings together pieces from 13 fine-arts magazines and full-text proceedings from conference proceedings.
The search on the home page searches the 2148 scholarly (ish) journals that the site indexes, all of which have major online content.
More information is available here:

http://jurnsearch.wordpress.com/about/

Go to http://www.jurn.org/