RSS Menu is a systemwide menu that allows you to read and organize your favourite RSS or Atom feeds.
The articles are automatically updated and you will get a notification when new articles are available or when some other event occurs. In addition to visual notification, you can also enable speech notification and choose one of the many built in voices.
It is also possible to integrate iTunes (for podcasts) and Safari (for RSS bookmarks) with RSS Menu. Key features include:

background application (doesn't get in your way and is accessible from anywhere)

very fast parsing engine

importing and exporting of OPML files

Growl and speech notification

many options to customize the menu

support for grouping feeds in submenus and adding seperators

support for using RSS Menu as an external reader in Safari (or any other application)

support for integration with iTunes and Safari

support for favourite icons (aka page icons)