I've been logging all specific referring urls for each weblog entry for a while now, but never really made them visible. Until now, that is. Try a couple of random entries and you're bound to see it in action somewhere...
To prevent the entry pages from turning into some sort of Google trap, search engine bots don't get to see the referrer lists at all (via a User-Agent check of common bot names).
I always thought this was a nice feature.