With PHP compiled as CGI or FastCGI, you can set permissions on files and folders maximum to 755. Otherwise your php script will produce an Internal Server Error. It's recommended to set permissions on folders to 755 and for files to 644. You can set the permissions on files and folders recursively using these commands:

Code:
find -type d -exec chmod 755 {} ';' -  it will set permissions on all folders to  755;
find -type f -exec chmod 644 {} ';' - it will set permissions on all files to 644