John Gruber explains in detail why he believes referrers are better than TrackBack at tracking conversations. His primary argument -- TrackBack is only available to TrackBack-enabled systems while referrers are avaiable to everyone via standard hyperlinks -- is appealing, but his system for displaying referrers isn't without problems.
The referrer log for this entry at Daring Fireball lists 113 visitors from 'www.kottke.org/', 32 from 'kottke.org/', 11 from 'www.kottke.org', 6 from 'www.kottke.org/index.html', and 1 from 'kottke.org/index.html'. Referrer logs that group visitors by the referring URL need to standardize these URLs before saving them to their database.
We do, however, love and use Mr. Gruber's fantastic SmartyPants as part of this site's poorly-crafted CMS.
Update: Our criticism is not aimed toward the practice of logging referrers per se. We simply prefer Dean Allen's method of arranging referrers in the order they were received, instead of by domain.