I was so busy over the weekend fighting bugs in the latest release of Dupin that I neglected to post that there actually are new versions available (here in the US it was Labor Day weekend, the irony of which is not lost on me).
Dupin is your iTunes duplicates manager.
As Macworld recently wrote, both Dupin and Dupin Lite "do a much better job than iTunes' Show Duplicate Items command of finding and zapping duplicate files, letting you easily tame overflowing libraries." Dupin has a few more power features, such as Re-Playlisting and Consolidate History. Dupin Lite has the same Get Dupes-Filter-Purge tools without the power-user features and is available at the Mac App Store.
Both now incorporate QuickLook auditioning (added in Dupin v2.6) and support Notifications. New to both is "dead" track detection, which will enable you to ignore or delete detected "dead" track duplicates.
You can download the latest version of Dupin here, or click "Check for Update" in your current version.
And in case you want to know:
The latest version of both Dupin and Dupin Lite were finished on August 8. I then submitted Dupin Lite to the App Store. A typical app review takes about five days and I figured I'd release them both the following week. Alas, because Dupin Lite required sandboxing, there were several App Store rejections to deal with before the kinks were ironed out. On August 29 Dupin Lite v1.3 was approved and I released the two apps.
Regretably, a major crashing bug was discovered almost immediately with Dupin 2.7. This bug was not detected during beta testing nor did I ever experience it. There was also a small issue with registration verification, but this was easily fixed in v2.7.1. The crashing issue didn't really come to light until it was discovered that a number formatter had been corrupted which was especially problematic for non-US systems users. This bug was isolated and fixed on September 2. Version 2.7.2 fixes that bug.
A secondary issue cropped up when it was reported that moving files during a Purge sometimes didn't work. This was easily replicated and fixed in 2.7.2 also.
I must thank the several beta-testers who took time out of their weekend to report and then assist with isolating and confirming a couple of bugs. I would not have been able to track the bugs or update Dupin as quickly without their assistance.