Directory and file permissions on a virtual host

Would some please provide me some simple rules for dealing with php scripts to fopen(), copy() and move_uploaded_file(). Environment is Linux, Apache on a virtual host I've spent a lot of time goggling, etc. and can find lot's of explanations for owner, group and world. They sound great; but don't work for me. This stuff worked on our previous host, it simply assigned "customer" to everything Here is my directory structure and permissions: /foo [user accessed php scripts] permissions= 755 /foo/data [simple text files] permissions = 777 files in /data permissions= 644 Have tried lots of other dir and file permissions owerships are our site handle. All I want to do is have the user http upload a file and use move_uploaded_file() to put it in my /foo/data Then later, a script fopen()s the file to read an append data to it. Just prior to appending to the file, I use copy() and rename it to anyname.bak I've fooled around around with shell access and chown and chmod to make things work; but, I can't believe this is necessary. Of course, once the script can't access the file, it can't change the permissions or ownership Help.