I really enjoy having the shell extension for NAnt; I can quickly right-click on my build file without directly navigating to a command prompt. For the client I have been working with recently, we are using Visual Studio 2005 Beta 2, enter MSBuild. MSBuild is a great tool, but I discovered they don't already have a context menu for their .*proj files. Adding the following entries to the registry will give you a right click menu to launch MSBuild for any of the .*proj files:
Navigate to HKEY\CLASSES\ROOT\*
Add a new key called “shell“ if it doesn't already exist.