Specto is a Linux-based desktop application that allows you to watch for configurable events and get notified instantly when updates are available. Things that you can monitor include websites, emails, files/folders, system processes and connection ports.

For example, Specto can watch a website for updates (or a syndication feed, or an image, etc), and notify you when there is activity (otherwise, Specto will just stay out of the way). This changes the way you work, because you can be informed of events instead of having to look out for them.