Not new – but worth repeating:
The Wisconsin Department of Financial Institutions (DFI) offers a nifty free search tool called CRIS(Corporate Registration Information System) for locating information about corporations in Wisconsin.
CRIS provides the official corporate name, registered agent address, principal office, state of incorporation, type of entity, prior corporate names, and notifications of merger or acquisition.
For more information on CRIS, see the recent article in the Wisconsin Law Journal, “Free Information in Wisconsin: Getting What You [Don’t] Pay For — CCAP & CRIS” by Law Librarians Association of Wisconsin (LLAW) member Jennifer Dedolph.
For more information on finding other company information, see “Mining for Company Nuggets” in the Wisconsin Lawyer by Carol Bannen, another LLAW member.