Here are links to known sites about the Rowley surname, its history and genealogy:

www.rowleyresearch.org
This is the really big Rowley Site set up by Tedd Rowley (now deceased), now a group effort. This site tries to keep record of every Rowley of America - a good source of Rowleys in USA census records in particular...

www.RowleyTales.com
ROWLEY family genealogy site, listing all known descendents of Daniel Rowley b. 1720 of Middlesex, Connecticut, and his many descendents. Includes a 6000+ name index. Related colonial names in New England: PARSONS, LANGRELL, HILLS, MANTLE, KNAPP, CHENEY, NOLFE, BEALE.