There are sophisticated code review tools out there. CodeCollaborator seems to be a good choice. Check their demo server where you can try it. See comparisons. But the main problem for me is that you need to install something on the server which means that you have to work with the IT department. So it is a little too much hassle for my tastes right now.
I think that the main obstacle for reviewing code is not being able to comment directly on code and not being able to see quickly which lines have review comments attached to them. So I did a quick internet search to see if there is a light weight standalone windows application that just does that. I couldn't find any, so I plan to write it myself. Notes:
* Read about code review. pdf: Lightweight Tool Support For Effective Code Reviews
* Make it an open source project and host it on sites like google code or sourceforge.
* I need a rapid prototyping environment. I know Delphi. Should I try VB or C#? Hmmm...
* Requirement screen shot:
Note for open source enthusiasts: You can check the Help Wanted page to look for projects that you can contribute to.