howto list all non-rpm installed files on system

[David Timms]

Anybody got some good ideas for listing every file on disk that is:
1. modified from default rpm install {eg config files}
2. not installed by any rpm
3. is a config file for a service - eg. web server /etc/httpd/conf.d/ 
and so on
4. is user data, config, files.
?

The purpose is to determine, say before an upgrade, what files need to 
be backed up.

locate / will give me all files on disk.
rpm -qfa will list all files installed by rpm
rpm -Va will tell files changed from what rpm installed.

Is there a tool that combines the above already ?

DaveT.