Where to adjust number of returned results on the /admin/people page? I know, don't hack core I know, you don't need to tell me. Don't Hack Core but I just need to display 1000 user records rows on the /admin/people page temporarily and I'll switch it back. I promise...
Install the Admininstration Views module; it converts that page to a View, which you can edit and set up with paging of your choice.