php, files, ownership....(was file manipulation)

Ok, I found out what was causing some of the people who were using my script and have it fail. They are on a shared server and apache is being run as user nobody, so therefore the script is being run as nobody. But the the files has to have user ownership foo foo. Is it at all possible to have a script run as one user and create files as another. Dont know if it is even safe?? Or could you point me in another direction? Thanks