Having recently picked up an iPod Touch, to replace my Classic, I've become very interested in HTML5's ability to navigate content offline.
In my environment I decided to create a separate directory for my manifest files. I'm also running IIS 7, on Server 2008 R2, so .manifest files are already defined for WPF.
So that that isn't an issue, I created a Web.config file in the manifest directory with the below contents. This effectively removes the already-defined MIME type, and replaces it with the one needed for the HTML5 functionality.
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<staticContent>
<remove fileExtension=".manifest" />
<mimeMap fileExtension=".manifest" mimeType="text/cache-manifest" />
</staticContent>
</system.webServer>
</configuration>
Any number of online sites can then be used to confirm that the file is passed with the correct type.