The people behind OpenMoko are amazing, and the tech they built for that still lives on in other projects like the Linux Kernel ist truly creative and trailblazing stuff.
Yes, it's nice to see that pmOS is already enabling experimentation into such things as graffiti-like gesture input. ISTR that people used to be quite proficient w/ the old graffiti system when it was around, so this might turn out to be the most usable input system on these devices, at least for power-users, and until wholly-open voice-recognition systems become viable.
I used this setup daily on a geeksphone keon for about a year. I liked it quite a bit. Sadly the screen got broken and 2G service was getting bad. :) I hope to bring this fun experience to another phone with pmos. After the modem starts working I can pull together what I had before for texting and contacts and push it to the shelli repo.
I also experimented quite a bit using pocketsphynx for voice recognition and espeak for synthesis. Some things worked pretty well if I kept the set of recognizable things small, which I liked anyway.