Just took some time to play around with the standalone trackback tool from Ben Trott. Works like a charm (once I upgraded my Perl installation).
Now, objects in CAREO have an associated URL for receiving trackback pings, as well as one for retrieving all trackbacks (if any) for that object.
Log into CAREO, and hit the button for any learning object. At the bottom of that screen will be a trackback URL, as well as a link to the existing trackback items.
This has the potential to be an extremely useful feature. I'd like to make it a little more integrated with the rest of CAREO, but the standalone Trackback works fine to test it out.