I recall seeing some domain-hashing solution on hackernews some months back, and built https://gist.githubusercontent.com/bradbeattie/c688e567e8564... in response. It's been working pretty well for me.

    $ ./pgen.py foobar.com foobar.net foobar.org
    Password? 
                    foobar.com: Aa0$d8~04h4W}Oj-MWA5  Aa0$eaxxF4XzaDaOnx5o
                    foobar.net: Aa0$q;7uc=@(4nSS5PIF  Aa0$pG5+6ekXTONYJXrE
                    foobar.org: Aa0$%YY$Dle*&(egUuL1  Aa0$y4AhSpO64xF+Aa/l