This is still a very rough draft. Just wanted to dump some ideas here I wrote in #kde-devel too. Going to rework this + add some mockups soon.

what do you think about making the file-kio a little more intelligent regarding permissions... what's annoying me often is the fact, that i have to start a 2nd filemanager using kdesu to gain write permissions on another dir.. this could be done IMHO by kio-file itself by spawning the write process as a user with write permissions on file/directory ... it should be relatively easy doable and would improve usability IMHO a lot ... does anything speaks against this? the UI could reflect this in a way like this: user tries to write to a directory/file on which he doesn't have write perms.. a dialog offers the user to do it as $owner of the file + there's an 'Other user' button, which allows to define the user freely or select it from a dropdown list... the same could apply to accessing (reading) directories and files where the user doesn't have permissions for... imagine how nice this would be, running kwrite for editing a sysconfig file as $user, but when trying to save the 'Save as..' dialog just asks for a password instead of failing ugly with a message like 'No permissions to write this file...' i see this now just from the user and usability perspective.. is there anything from a developer POV which wouldn't make this possible?