Apparently the government listened to my assertion that I would only vote on an open source electronic voting system. This article reports on hearings within the California State Senate about using open source software in election systems. The article also points to several large companies that are actively using open source:
A number of private businesses, including Bank of America, Amazon.com, America Online (AOL), DreamWorks, Charles Schwab, IBM, and Merrill Lynch, have begun using open source software for some applications. Furthermore, the Department of Defense, the State of Massachusetts, and the California Air Resources Board have begun to migrate some of their computer systems from proprietary to open source software.