Tux
Since I'm a student and have roughly zero free time, my boss was kind enough to get me a laptop for working at home. This is Tux. Tux is an iBook G4 running OS X and Debian Linux. More or less the only reason OS X is still there is Broadcom sucks and wont release drivers for their 802.11 chipsets, so I'm stuck without a wireless card in Linux.
If anyone really cared, I use Enlightenment with the Ganymede theme for E and GTK. Since there isn't one for KDE, I'm using dark blue colors with the "Keramik" style, which looks pretty good. I've compiled the E17 dependancies for Entrance so that I can use it rather than {k,g,x}dm. The packages are for PowerPC processors with Altivec and OpenGL.
Tux ends up being my "scratch pad" for testing out new software. Some new things it is running are laptop-mode and prelink. Laptop-mode prevents Linux from writing out data for up to a configurable length of time, which leads to better battery life. Prelink precomputes all of the libraries a program will need, so it doesn't need to be done when the programs are executed leading to faster startup times. Additionally, it can randomize the lload locations of libraries, leading to slightly improvied security. Finally, the big test is SELinux, a manditory access control system for Linux.