I will be out Thursday through Saturday traveling to two different conferences. I will be presenting my The Heart of Change: Julius Caesar and the End of the Roman Republic paper at the Michigan Association of Middle School Educators conference in Petoskey, Michigan on Thursday morning. (I am there by invitation. I would not have thought to present this paper to middle school educators but the conference chair thought it was a good idea!)
On Friday and Saturday I will be attending the Scholarship and Libraries in Transition:A Dialogue about the Impacts of Mass Digitization Projects symposium in Ann Arbor, Michigan. I do not have to present but I hope to have some good conversations while I am there.
Obviously, much of the dialogue at this conference will deal with Google Books. Despite some legal troubles, there is a lot here already including a great deal of public domain pre-1923 material dealing with presidents. For example, type in "Franklin Pierce" date:1800-1860 and see all the neat stuff that comes up!