Virtual Museums and Online Exhibits
Multi-disciplinary
Yale Museums Online: http://learninglynx.blogspot.com/2011/05/yale-museums-online.html
Many many museums: http://learninglynx.blogspot.com/2011/09/museums.html
Art, science, and history: http://www.freetech4teachers.com/2013/04/7-good-virtual-tours-for-students.html#.UWHLxpNwqSr
Art
Examine 17 of the World's Best Art Museums and make an art collection: http://www.googleartproject.com/
Virtual Tour of an art museum: http://learninglynx.blogspot.com/2010/02/virtual-tour-of-art-museum.html
Country Dogs Explore Art Museum: http://learninglynx.blogspot.com/2010/02/country-dogs-explore-art.html
Freer and Sackler Galleries online: http://learninglynx.blogspot.com/2010/02/freer-and-sackler-gallery-art-online.html
SF MOMA Tour (cool!): http://learninglynx.blogspot.com/2010/03/cool-online-art-museum-sfmoma.html
NYPL Digital Gallery: http://learninglynx.blogspot.com/2010/06/nypl-digital-gallery.html
Tour the Louvre: http://learninglynx.blogspot.com/2010/09/go-to-louvre-virtually.html
Sistine Chapel: http://learninglynx.blogspot.com/2012/03/sistine-chapel.html
Various: http://www.freetech4teachers.com/2013/04/7-good-virtual-tours-for-students.html#.UWHLxpNwqSr
History
Online Museum Tours: http://learninglynx.blogspot.com/2010/08/online-tours-of-british-museum-history.html
Science history and US History: http://www.freetech4teachers.com/2013/04/7-good-virtual-tours-for-students.html#.UWHLxpNwqSr
Archaeology Museums
Virtual Museum: http://learninglynx.blogspot.com/2010/02/virtual-archaeology-museum.html
Museums: http://learninglynx.blogspot.com/2010/02/museums-with-archaeology.html
Fraser Museum: http://learninglynx.blogspot.com/2010/02/fraser-museum.html
Penn Museum: http://learninglynx.blogspot.com/2010/02/penn-museum-of-archaeology.html