A couple of months ago, using Google co-op's Custom Search Engine (CSE) capability, Lukethelibrarian explains on his blog that he created a custom search engine that will perform a search across all the english language journals found in the Directory of Open Access Journals (DOAJ) collection.
Try out the DOAJ search engine for english journal content!
Lukethelibrarian is also looking for volunteers to help him refine his DOAJ CSE service. To volunteer, go to the main search page of his CSE and look for the "volunteer" link in the lower left part of the page. He is also looking forward to any suggestions or feedback.