I currently have a small dataset of oregon ballot measures results broken down by county in a series of CSV files here (https://github.com/travishathaway/oregon-measures/tree/master/data). I am currently missing 2002 and could also provide 1996 if people are interested. In that same repository, I also have a PostgreSQL database dump that has a complete set of ballot measures (1996 - 2012). The database dump file currently requires that PostGIS be installed to properly work, but if people are interested, I could modify it to remove that requirement.
I retrieved this data from the Oregon Secretary of State's website (http://sos.oregon.gov/elections/Pages/electionhistory.aspx). In order to get it in to CSV I had to parse it from a series of PDFs and HTML documents, which we all know isn't the best format for storing data.
If there is interest, I could work on expanding this data set more. Also, please let me know what I can do in order to make the data I currently have accessible from this website.