Security question

I am creating a directory on my webserver (Linux/Apache) to hold images that are uploaded by the administrators of the site but I am concerned about the permissions to place on the directory. Obviously PHP (runs as user nobody) has to have write privileges for the directory, so I can either create a world writable directory and use .htaccess to deny PUT access or create a directory owned by the nobody user and only allow the owner write privileges. Can anyone tell me which of these options is the most secure, or suggest an alternative method? Thanks in advance, James.