No subject

There is an update-motd job that checks for updates available, so the
number of updates available will be listed at the end of your
/etc/motd:

    Linux t61p 2.6.28-8-generic #26-Ubuntu SMP Wed Feb 25 04:27:53 UTC
2009 x86_64

    The programs included with the Ubuntu system are free software;
    the exact distribution terms for each program are described in the
    individual files in /usr/share/doc/*/copyright.

    Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
    applicable law.

    To access official Ubuntu documentation, please visit:
    http://help.ubuntu.com/

    125 packages can be updated.
    0 updates are security updates.


And, as Jan mentioned, if you're running screen, you will have the
number of updates available as white text on a red background, as seen
at:
 * http://people.ubuntu.com/~kirkland/Screenshot-ec2-cost.png
An exclamation point is appended if any updates are security updates.

Obviously, this does not solve the desktop case. But on
command-line-only servers, this is exceptionally useful!

:-Dustin