Once installed as a bookmark in your browser, the Legal Citation Finder (Citer) searches for the full-text of a standard citation to Federal law, regs, and appellate cases. Details are on the Cornell LII website. There are plans to expand the Citer to find state courts, then maybe law journals. There’s one version of the Citation Finder for Internet Explorer, another for Firefox and other non-IE browsers. Thanks to the Law Librarian blog for the link.