Forum Moderators: open
(eg past 3 months, past 6 months, only .com, only .org etc)
Easiest way is to use the SOAP web API
[google.com...]
to grab various variant SERPS, and then merge the resultant lists.
You can get well beyond 1000 with some confidence, but you could always be missing tha actual 1001st, and you'd never know.
Still, you end up with a legally automated query that yo can run every day, and dump the results into a database for analysis, so it's not all bad.