There is not an enourmous amount of deployment control where I work at the moment. And while there is a long term plan to create a build script that deals with deployment at the
I use ant as my build tool, so I have an ant target that stores the output of svnversion in the file svn-version. That target is a dependency of all the major entry points, so every time I run ant, svn-version is updated. I have the packaging operations include svn-version in all deliverable tar and zip files. So I can always look in svn-version to find out what version of code has been installed.
Whatever build tool you are using, you should be able to do the same. if the data from svnversion isn't sufficient, you may want to add the output of svn info to the file as well.