Project Description
Compile time checking of resource and Xact cue names and deploying one .zip file instead of hundreds of .xnb files is why you should download this right now.

Here are some more reasons why you should use this tool:
Download the latest release now to get started and you will never deploy .xnb files again. You will find a sample project to help you get started. Just check out the readme.txt file and you'll be set.

For your convenience here's a sample post build event that I used to get all my .xnb and .txt files into the .zip file and usable as content pipeline resources:
$(ProjectDir)..\bin\debug\ZipArchiveCreator.exe "$(TargetDir).xnb|$(ProjectDir)Text\.txt" $(OutputDir)Content.zip $(ProjectDir)ResourceId.cs TestContentGame ResourceId $(ProjectDir)Audio\Sound.xap

To use this on XBOX, you'll need to get the System.IO.Compression implemented on the .NET Compact Framework 2.0, here is one web site that has implemented it:
http://www.aspecto-software.com/rw/applications/developer/compression/index.html
(I believe that the .NET compact framework will officially support System.IO.Compression in version 3.5 - whether this will appear on the XBox 360 as well remains to be seen...)