Held in San Francisco, California directly following Macworld Expo on January 13 through to the 15, 2006, the Worldwide Newton Conference included a presentation by Paul Guyot of Kallisys in which he demonstrated Einstein, a Newton OS emulator for Linux-based PDAs with X11 support. Guyot's presentation (PDF) recapped Einstein's development from its slow and buggy start as an emulator on Mac OS X to its current incarnation as a slow, buggy emulator running on his Sharp Zaurus SL5500. Though he says the new version run seven times faster than the previous see foresees greater speed improvements and even color in Einstein's future.

More info here and a nice pic here.