Gmail has a feature called “feeds for unread messages”, for e.g. the feed http://mail.google.com/mail/feed/atom/ shows the most recent unread items from your inbox. Gmail also offers feeds for your labels: http://mail.google.com/mail/feed/atom/labelname/, but it would be nice to have a comprehensive listing of all the unread messages, not just the ones that have a certain label. As you probably know, "unread" is one of the many built-in labels in Gmail, so you can use it to obtain this feed: http://mail.google.com/mail/feed/atom/unread/. In the URLs above, you can replace "http" with "https" for more security.