As written, this flavour requires the
lastmodified (with a small patch, included) plugins. If you're running Blosxom 2.0, you can grab my Atom 0.2 flavour files here. It uses a CDATA encoded version of the individual posts. If you're enough of a stud so that your blog's totally valid XHTML you might want to modify
story.atom to serve the non-encoded representation instead. I wasn't going there with my own stuff-- some of these entries get written after midnight, but hey, knock yourself out.
Beam me up, Scotty!