So I was grumping to myself that my nice, big, cheap Timex digital clock wasn't doing the best job for the ham station. I had modified it for 24 hour time, but the 10 hours digit could only provide a squiggle and not a proper "2" for 20-23 hours. That, and it is physically in the wrong place (away from my computer screen) and it doesn't show civil (local) time along with UTC. I've searched for a good hardware solution with no luck.
Then I looked at some of the many Linux clock options out there. None of those was exactly right for me. I wanted digits I could read across the room, but that would fit onto my crowded Linux desktop. Anyway, it's always more fun to use software you build yourself. I pulled out my Python and wxWidgets (wxPython) references and set to it. As with designing and building your own hardware, half the reward is the stuff you learn along the way.
So here is the product. If it looks like it might be useful to you, it should run on any recent Linux system with no hassles. I also checked it on Windows XP and Windows 7 for good measure. It works there, but you will have to download Python and wxPython from the web. (Linux systems like Ubuntu provide these as part of their repository system.) MacOS will likely also support this program.
This is free (as in beer) and open source software, distributed under the GNU General Public License. That means you can download it and modify it to your taste, as long as you are willing to make your improved source available to the community if and when you distribute your new version.
In a future version, it might be worth working on desktop space efficiency. You notice that nearly half the window area is wasted on Gnome's frame decorations and menus. That could be reduced by using "shaped" frames at the cost of complicating the code and creating non-standard window behavior.