I've started development on an alternative keyboard mapping at http://technomadic.org/greg/Projects/keyboard/. It started as a simple thing so that I could have a layout that I felt made sense. It's since grown into much more in my mind. The possibility of a single keyboard mapping useful throughout North America and Europe, and especially so to typographers and mathematicians. And also consistent across different computer systems such as Windows, Linux, Solaris, and OS X.
The OS X version is the most advanced so far (because the data format is very powerful) and there is no Windows version yet (because I don't know how to make the DLL). The xmodmap files (for various Unix platforms) fall in the middle ground.
I've set up a mailing list to discuss and further develop the keymappings. I would appreciate it if anyone interested would take a few minutes to take a look and make any suggestions.
Thank you.