I was getting annoyed by MSNBot trying to index /reader/default.aspx. So, I decided to deploy a Robots.txt file. In case anyone wants a template for a Community Server Robots.txt file, here it is. I don't know what the Downloads folder is used for (other than what I found at this thread), so I've included it anyway.

# Robots.txt file for http://domain
# User-agent: *
Disallow: /aspnet_client/
Disallow: /ControlPanel/
Disallow: /Downloads/
Disallow: /Emoticons/
Disallow: /FreeTextBox3/
Disallow: /Ink/
Disallow: /Installer/
Disallow: /Languages/
Disallow: /Messages/
Disallow: /reader/
Disallow: /Themes/
Disallow: /User/
Disallow: /Utility/