Memory usage of gnome-power-manager 2.16.x : 2.7MiB
Memory usage of gnome-power-manager 2.17.x : 1.7MiB
On a side note, gnome-power-manager 2.16.x was pretty much synchronous with hard-coded sequences of operations and functions depending on events. 2.17.x is much better code IMO, with most of the events happening asynchronously and with separate state machines. This makes the code much easier to understand and modify, and should squash some weird timing bugs. It also makes adding new functionality as easy to add as dropping in a couple of gobjects and hooking up some signals.
CVS versions of hal, hal-info, pm-utils, PolicyKit, libnotify, GtkUnique and of course gnome-power-manager are in the utopia FC6 repo. Caveat emptor.