The California Secretary of State's office has a page on election systems at "http://www.ss.ca.gov/elections/elections_vs.htm" that includes links to PDF documents listing the 58 counties in the state and what voting systems they used for the November 2002 election and what voting systems they will use for the October 2003 recall election. There is also a link to another document with a list of all voting systems certified for use in California that includes even more detail (like manufacturers' addresses).
Kluwer wrote on secure electronic voting and technologies with a chapter by Ed Gerck.
With the US and other countries poised to test Internet voting in 2004/6, this book may provide useful, timely points for the discussion of the assurances thereof --