The City Directories of Rochester, New York are online at this URL:
http://www.libraryweb.org/rochcitydir/citydirectories.html

They have digitalised directories >from the 1820's to the 1890's and are working
on getting through to the 1930 directory, where their efforts will stop.

Martha Levinson Lev-Zion
Israel Genealogical Society - Negev