Best way to do a 301 redirect from non-www to www. in IIS7.5?
I would suggest that you install the URL ReWrite module for IIS 7 to do this for you. You would add a rule that looked soemthing like this
<rule name="Canonical Host Name" stopProcessing="true">
<match url="(.*)" />
<conditions>
<add input="{HTTP_HOST}" negate="true" pattern="somedomain\.com$" />
</conditions>
<action type="Redirect" url="http://www.somedomain.com{R:1}" redirectType="Permanent" />
</rule>
See this article for some hints and tips on URL ReWrite.