Examples of Montages on the web:

Dada Artists
http://www.arts.usf.edu/art/arhtest/lec9d.html

John Heartfield
http://www.towson.edu/heartfield/art/art.html

Katherine Weinstein
http://www.anti-art.com/othart/kking1.htm

Romare Bearden
http://www.albrightknox.org/ArtStart/Bearden.htm

Romare Bearden http://www.pbs.org/wnet/americanvisions/gallery/g_7.9.street.html

Hanna Hoch http://artchive.com/artchive/H/hoch/das_schoene_madchen.jpg

Hanna Hoch
http://artchive.com/artchive/H/hoch/high_finance.jpg

Hanna Hoch
http://artchive.com/artchive/H/hoch/da_dandy.jpg

John Heartfield
http://www.brasscheck.com/heartfield/gallery.html

John Heartfield
http://www.brasscheck.com/heartfield/rise.html

Click on images to see an enlarged version