Form S-2 was a simplified, optional registration form used by companies required to report under the 1934 Act. It was phased out in 2005.
For more information from the SEC about the new form requirements, see their report, "Changeover to the SEC’s New Smaller Reporting Company System by Small Business Issuers and Non-Accelerated Filer Companies: A Small Entity Compliance Guide," or visit the SEC website (http://www.sec.gov/).