I tried and spent a few hours yesterday evening playing with the
FontMapper script but to no joy...
Basically this script mounts (using the
mount --bind Linux-specific option which allows mounting into existing file systems) a user-writable FONT folder in lieu of (
yet another frenchism 
) the
/opt/sony/application/FONT folder.
The goal is to use the font files stored in this user-writable folder to change the LRF fonts more easily than by flashing.
I tried mounting a user-writable
adobe folder into
/opt/sony/application, but it didn't work. I guessed that the target folder had to exist, so I tried creating it, but it didn't work either (maybe this is a read-only space ? because it's in the firmware ?).
Then, I issued a
cp -R command to copy all the files in the
/opt/sony/application to the user-writable space, added a
adobe folder to this copy, and tried
mount --bind to mount it in
/opt/sony/application ; I thought that it would work, but it didn't...
I think that my basic idea is not bad, but I need help from people who know more than me the PRS filesystem and limitations ; yes this means you,
Igorsk 
Also, maybe
alanine could help us too, he was the nice guy who wrote the
FontMapper script...
At least I tried !
David.
PS : I take this opportunity to post a text file containing the result of a
ls -laR command into the Sony Reader, it is interesting, IMHO
