Those of you with Pennsylvania ancestors may find something of interest in the Historical Society of Pennsylvania website. It offers many on-line images from its collection as well as informative articles, and more are being added...especially in anticipation of the sesquicentennial of the Civil War in 2011.
A casual review of the site shows that most of its offerings are personal papers rather than reams of vital statistics. But those papers can reveal many hidden treasures.
Check out the collection at http://www.hsp.org/default.aspx?id=976