Fedora Core 5 comes with the new "gnome-power-manager" which is rather good, as it provides a few more features than the old battery applet such as suspend-to-ram (suspend) and suspend-to-disk (hibernate). However, I can't get my Compaq Presario 2104EU to suspend-to-ram properly; it suspends ok, but powering on just gives me a blank screen. I'd tried to add boot options such as 'acpi_sleep=s3_bios', but to no avail. Either it's a flaky bios or I need to remove some modules before putting the laptop into suspend. What does work is hibernate, though I do have to run 'service network restart' upon resume as it seems to loose its network settings.
For FC5 you can update the 'gnome-power-manager' to the lastest version by adding this file to /etc/yum.repos.d/ and running:
# yum -y update gnome-power-manager.i386
Restarting your gnome session you get this new applet:
Choosing "information" from the menu displays extra's that aren't on the official FC5 release: