Daemon which notifies about package updates.

Update Notifier will check for the availability of new packages for your Debian system on a daily basis. When it detects new versions of the packages installed on the system are available, it will add an icon on the desktop notification area.

It will work with any Desktop system that implements the FreeDesktop notification area specification, like GNOME, KDE and XFCE

http://packages.debian.org/unstable/source/update-notifier