ContributionSurveyor is a tool that examines all of the edits of a user and generates a page that groups them by article with diff links for each one, and sorts them so that articles that the user made major contributions to are listed near the top. For a small sample, see User:Dcoetzee/ContributionSurveyor:OSUHEY. They're useful for reviewing users who are known to have been long-term copyright violators, but are also just interesting for reviewing general editing trends and areas of interest of a user. Unfortunately the tool must perform a query for each edit of the user, so I only run it offline at the moment and it takes hours. You can download a copy of the tool with C# source (public domain) and basic instructions of use from:
Below are some completed reports.