aptitude show ubuntu-laptop-mode
... Support for reducing hard drive power
consumption Laptop mode is a Linux
kernel feature that allows the system
to reduce power consumption by
allowing the hard drive to spin down
for longer periods of time. This
package contains a script to control
these kernel parameters.
aptitude show laptop-mode-tools
Scripts to spin down hard drive and
save power Laptop mode is a Linux
kernel feature that allows your laptop
to save considerable power, by
allowing the hard drive to spin down
for longer periods of time. This
package contains the userland scripts
that are needed to enable laptop
mode. It includes support for
automatically enabling laptop mode
when the computer is working on
batteries. It also supports various
other power management features, such
as starting and stopping daemons
depending on power mode,
automatically hibernating if battery
levels are too low, and adjusting
terminal blanking and X11 screen
blanking.
So it definitely looks like laptop-mode-tools has more features and might do your laptop more good.