Since you have a strong interest in visualizations of physics phenomena, and you're already teaching your nieces and nephews how to write Python, I'd like to suggest that you check out VPython, which is a series of 3D extensions to Python. In particular I think you'll be intrigued by these examples which visualize everything from wave superposition, to magnetic fields, to concepts from relativity. For immediate gratification, the author of that examples page also has Wiimote integration, so you can bridge interest that your relatives might have in video games into an interactive experience in your physics environment.

Good luck!

I also used to work with this "hair trigger IT moron" at the university where we both got our top-tier Computer Science degrees. Hands down, he is brilliant. I have seen him at his best, which includes: writing an entire network registration software suite for use at large institutions, diagnosing bizarro network problems, and managing network security issues. It is rather unfortunate that he was quoted as saying he was confident that it wasn't a Cisco-related problem. While that ended up not being the case, I have no doubt in my mind that he had reasonable cause to think so originally. I have always seen Kevin as a rising star, and I am confident that he will continue to do great things.