The Institute of Governmental Studies has released guides to the two ballot measures on the June 5 California Primary Election ballot on the California Choices website at:
http://californiachoices.org/ballot-measures-2012-6
In addition to voter resources and in-depth analyses of the propositions, the site features a View Endorsements and Share Your Vote page where you can compare endorsements from political parties, unions, newspapers, and other organizations, and share how you are voting with friends and family via email or Facebook.
http://californiachoices.org/ballot-measures-2012-6/endorsements
California Choices is a collaborative effort by the Institute of Governmental Studies at UC Berkeley, the nonpartisan nonprofit organization Next 10, and the Department of Political Science at the University of California, San Diego.