How to create a backup of your starred items in Google Reader, should the need ever arise:

• Log in to Google Reader
• Click ‘Settings‘ in the top-right of the window
• Click the ‘Tags‘ tab
• Check the “Your starred items” box
• Click the “Change sharing…” dropdown box and select “public“
• Now click on ‘View public page‘ which has appeared to the right of “Your starred items” (this will open in a new window by default)
• In the right-hand column there is a link to a feed. Right-click it and save it to disk.

Congratulations, you now have an Atom feed of your starred items to do with as you wish. With any luck it will even be valid.