kilot, jpilot, and gpilot
I might be able to find an old version of kpilot, but I would assume that since it's not now in Kubuntu, any older version would not work very well in the current KDE environment.
jpilot does indeed work under the latest Kubuntu, but it's not at all integrated with KDE -- not surprising for a program that apparently hasn't been significantly changed since the year 2000. It works pretty well on its own terms, but its database, which is not configurable, seems not to be compatible with korganizer and kaddressbook.
I tried gpilot, but it lacks conduits for an addressbook or a calendar, let alone the addressbook and calendar used by KDE. And syncing it seems to require a gnome applet that isn't available in the KDE environment.