This is a process that is becoming more and more important as we offload a ton of our page processing to .js files as opposed to HTML files processed by the server. This is because we are doing more client templating and logical processing on the client and not on the server.
Here is a great blog post that goes through automating the minification process through Visual Studio build events.
There are other ways – I also think an HTTP handler that does this is nice if you want to have a more easily updatable source tree where you don’t need to keep track of a debug and live version of a file on top of your other versioning.
Here is a link to an http handler which allows you to minify js files inline.
and via [Robert Pohl]
more later - joel