Google has announced that a new feature in Google Reader which allows you to track any changes in a website even if the website does not have feed. This new feature creates a custom feed for sites which does not have a feed of its own.
To get this feature working all that you have to do is paste the URL of the page that you want to track in Reader's "Add a subscription" field and click on "Create a feed". After that is done, Reader will periodically visit the page and publish the changes.
If you do not want Google to create feeds for your page, Google also gives you the option to opt out of the feature.