on a fresh system, there's a good chance that the associated config file is actually in /boot, with the name config-<whatever version>. at least, that's a good place to start.
rday
p.s. the 2.6 kernel comes with a config option to bury the config file inside the actual kernel itself. IIRC, to get at that file, you'd use a utility called extract-ikconfig.
Thanks for the replies, this was what I was looking for.
cheers Edwin