If you have data in Excel and you want to hide rows with duplicate entries, it's super easy:
1. Select the data you want to filter
2. Data | Filter | Advanced Filter
3. Click “Unique Records Only“
Excel will then hide rows that are duplicates of each other. I use this when putting together stats for the Exchange blog. At one stage in the process, I have a CSV full of rows with the article title and search terms used to get to that article. I want to let the authors of the blog know what terms were used to get to their articles, so I filter out the duplicate rows to make it more digestable.