VSTS and VSX Cocktail: Team Review
There are a few Code Review projects on CodePlex and they apply to different situations. But the more sophisticated one and the one I really like and have used in more implementations is TeamReview, by JB Brown, who recently added me as a contributor to the project so I could help with a bug I had identified, but all the credit belongs to him, I am clarifying that because you will see my name there but JB has done all the work.
But JB's implementation, which uses not just the Team System customizations but also Visual Studio Extensibility (VSX) as well, has allowed me to use Team Review for other things, not just code reviews. For instance, development tasks that include pointers to specific source code. Willy-Peter Schaub recently created a TeamReview workflow poster (another one of his already famous posters) and a review blog post, take a look at them for the best visual representation of what I am talking about:
The poster:
http://dotnet.org.za/willy/archive/2008/09/01/tfs-new-quick-reference-poster-an-overview-of-teamreview.aspx
Willy-Peter's blog post about TeamReview:
http://dotnet.org.za/willy/archive/2008/08/26/a-quick-look-at-teamreview.aspx