Can I get new, but *not* updated packages from "unstable"?

["Joe Emenaker" <jemenake@genesiscom.com>]

For a long time, I've had a policy of updating my servers from stable *and*
unstable because I wanted the newly packaged stuff but also, more
importantly, because I wanted bug fixes for security holes asap... without
having to wait for the next official release of Debian.

Well, it seems that bug fixed versions are placed in "stable" as well, so I
don't need "unstable" for that. However, I still would like to get to all of
the new packages there.

Is there anyway to use unstable *only* for the packages that *don't* exist
in "stable"?

- Joe