I needed to be able to compress my JavaScript files, and I like to use the YUI compressor to do this.  Found an even easier way to do this using Visual Studio, by creating an external tool as mentioned in this blog:  http://blog.lavablast.com/post/2009/05/YUI-Compressor-for-Visual-Studio.aspx

Also, there is an option for an MS build task: http://www.coderjournal.com/2008/05/how-to-create-a-yui-compressor-msbuild-task/

Really cool, very helpful.