I'm working on a PHP project for a client in which the script generates PHP files based on database content which are used as the pages for the site.

The script is running as owner/group nobody:nobody and the filesystem in which it needs to write these files to is john:users. The only way it will write to it is if the filesystem has permissions for other to write (and obviously it needs others to read and execute as well) resulting in chmod 777. Obviously we don't want this permissions.

I do not have chown access... what else can I do?

Sounds like you might want to create a new group that has write permissions to the directory in question, and has both "nobody" and "john" as members?

PS:
Clearly almost any viable solution will probably require somebody with "root" access to make the appropriate "groupadd", "moduser" and "chmod" commands...

I was able to resolve this by using php-cgiwrap