I just stumbled across genealogy records available (for free) on the Internet Archive, a repository of Internet info that chronicles changes on the Web and stores all kinds of historical and cultural data. Want to see a video of old Commodore 64 video games? You can find 'em on the Internet Archive.
The link to the genealogy holdings takes you to holdings shared by the Allen County Public Library Genealogy Center in Fort Wayne, Indiana; Robarts Library at the University of Toronto; the University of Illinois Urbana-Champaign Library; the National Library of Scotland; and the Boston Public Library.
Info ranges from publications about Mayflower descendants to Passenger and Crew Vessel Lists for NYC, 1910 and 1940 and other years.
Check it out! Maybe you'll find something you were looking for.
2022 Update: I've had great luck using the Internet Archive to access phone directories and find home addresses for ancestors who are in the 1950 US Census.