Lots of people has recently been striving to get down the memory requirement of thier GNOME application or deamon.
I've recently created an out of process (the old one was in-process for each instance) graphing program, gnome-power-statistics. The displayable name is yet to be decided, but it's basically a graph viewer that talks to gnome-power-manager over DBUS to the shiny new org.gnome.PowerManager.Statistics interface.
Notice the surge in power usage as I start “make distcheck” on HAL in the 23rd minute.
Now, I know the application really needs some HIG love, but this removes a whole chunk of memory from the session daemon, namely 500kb of writable memory.