Beall's List of (possibly, potentially) Predatory, Open-Access Publishers (Archived)
These are questionable, scholarly open-access publishers. Maintained by metadata librarian Jeffrey Beall, who "recommends that scholars not do any business with these publishers, including submitting articles, serving as editors or on editorial boards, or advertising with them. Also, articles published in these publishers' journals should be given extra scrutiny in the process of evaluation for tenure and promotion.