I recently came upon The Free Library in a Google search and spent some time, with interest, on the site. Despite some serious pitfalls, there is some great information on the site for genealogists willing to do some digging. That is, if you can get past the *cough* aesthetic struggles *coughcough* of the site, and can handle its untoward and awkward navigation.
The site does provide a keyword, title, author and subject search, which functions fairly well. You can also browse journal titles by subject, via the homepage. Once you have located a title you are interested in, you can subscribe to an RSS feed for that title and be notified when new content is added.
Some titles of notable interest to genealogists:
* The Journal of Southern History
* The Loyalist Gazette (Revolutionary War)
* Afro-Americans in New York Life and History
* Journal of Social History
Mostly of the historical ilk, but then all genealogists are historians, if all historians are not genealogists!