The Sequence Browser integrates with Lutz Roeder's .NET Reflector. It displays kinda UML sequence diagrams for method calls. It's actually just a prototype, but I thought I should release the source code. Maybe someone would be interested to take the idea and build on it. You could use this code to improve the Sequence Browser or include it in your own product.
To see the Sequence Browser in action, you have to build it and add it as an add-in for .NET Reflector.
You can then navigate for example to System.Windows.Forms.Button.ProcessMnemonic, right-click and invoke "Sequence Browser".
If the "Sequence Browser" command is not enabled, you may have to insist by trying on other nodes. Reflector seems not to work always well.
Here is a picture of what you should see.
You can try to change the depth to 0 and hit the Redisplay button.
Note: every text is a link.
I'd be interested to know what you do with this idea/code, please let me know. I would enjoy to share with you the extra ideas I have for this kind of tool.