I am working on a web site on a free web hosting service, which isn't too bad for learning but I am going to be going to a real service soon, well as soon as I figure out what I need.

What I want to be able to do is allow certain users to read, write and execute files, to enable them to make changes to their profile and to their data. Other users that will use this data I only want to be able to access it but not change the data. I know if you had your own server you could do this easily, but is it possible to do this with a reasonably priced hosting service? There are a bunch of reasons why I want this to be done with directories and files rather than a database. Mostly has to do with speed.

Kind of a general question, but if anyone has any insight, please chime in.