Way back in the days when I got my first IBM compatible PC running MS-DOS and Microsoft Windows 3.1 there was a feature in the Windows file manager I have really missed over the years since 3.1 became redundant. It's the split screen mode.
Well I shall miss it not a minute more. For Nautilus has just such a feature. Simply open Nautilus and press F3. Each pain can point to it's own directory. Which is handy considering I connect to FTP servers using Nautilus.