A similar feature is now available in Google Reader and it's cleverly integrated: click on "Add subscription", type the address of a web page and Google Reader will automatically generate a feed if it can't detect one.
"We provide short snippets of page changes to help you quickly decide if the page is worth revisiting and we're working on improving the quality of these snippets," says Brian Shih.
"Reader may not always detect updates to your content. Currently, only English-language content in HTML format is supported. In addition, updates to content in frames are not detected; nor are updates to content that requires sign-in to view," mentions a help center article, which also informs that webmasters can prevent Google from monitoring web pages by using the features that block Googlebot from crawling or caching web pages. This suggests that Google Reader's page monitoring uses data from Google's search index and the changes may not be detected quickly if the web page is not popular or it doesn't change often.
Since I rarely visit Google's homepage, generating a feed for google.com or for other international Google homepages is a great way to track all the doodles and the promotional messages.
For now, Page2RSS offers more features (posts have better titles, you can view a cached version of the page), but Google Reader is more reliable. For example, Page2RSS doesn't show the latest changes for google.com.
Tip: to find the URL of the feed generated by Google, click on "show details" and you'll find a URL like:
http://www.google.com/notificationservice/webchanges/webfeeds/11009120664050806769