splashy works great on startup and shutdown, but not while hibernating with pm-utils.
uswsup would work with splashy but the default package from community does not include splashy support.

Compiling the lastest official version 0.8 from suspend.sourceforge.net with ‘–enable-splashy’ raises an error:

checking for splashy_open in -lsplashy... no
configure: error: Required libsplashy was not found

The newer version 0.9 from git.kernel.org fixes that error.

After compilation, hibernating and resuming will display the installed splashy screen.


Here’s the package providing uswsusp with splashy support: uswsusp-splashy-git

Gnome 2.30 (Ubuntu 10.04) renamed the DeviceKit.Power to UPower:

$ echo 'dbus-send --system --print-reply --dest=org.freedesktop.UPower /org/freedesktop/UPower org.freedesktop.UPower.Hibernate' | at now + 30 minutes

There’s also suspend.
Shutdown (Stop) and Reboot (Restart) works over the system call: org.freedesktop.ConsoleKit

Or use this tool

—

Pre Gnome 2.30

As of Ubuntu 9.10, the gnome-power-cmd doesn’t exist anymore..but…
D-Bus to the rescue!!

Hibernate after 30 Minutes:

$ echo 'dbus-send --system --print-reply --dest=org.freedesktop.DeviceKit.Power /org/freedesktop/DeviceKit/Power org.freedesktop.DeviceKit.Power.Hibernate' | at now + 30 minutes

There’s also suspend.
Shutdown, reboot and logout works over the session call: org.gnome.SessionManager

Or use this tool

—

Pre Ubuntu 9.10:

Suspend:

$ gnome-power-cmd suspend

Hibernate after 30 Minutes:

$ echo 'gnome-power-cmd hibernate' | at now + 30 minutes
job 1 at Mon Sep  7 15:10:00 2009

You can review and delete any queued job with:

$ atq
1	Mon Sep  7 15:10:00 2009 a wag
 
$ atrm 1

The gnome-power-cmd also accepts shutdown and reboot.