I posted earlier this month of my love for the recently refreshed Google Reader, though for many users it's still missing one key feature: a notification utility for new headlines. Some newsreader apps and services have all sorts of widgets and menubar apps that can notify users of new content in their favorite feeds, and now the new Google Reader has one as well, the Google Reader Notifier (unofficial, not provided by Google). Based on GROSX (which worked on the previous version of Google Reader), this notifier can check your entire Google Reader account for new headlines, or you can give it a specific label to watch. While the Google Reader Notifier it doesn't provide popup notifications like Google's official notifiers, it can display an unread count. One downside to those who aren't quite as RSS obsessed as others is that it can only be set to check at intervals of 5, 10 or 30 minutes - there are no lengthier options like 1 hour, 3 hours, etc. Still, this is a nice utility that shakes hands well with a Google Labs service.
Google Reader Notifier is free and available from the developer's site.