And, for the adventurous:
This package will replace the original sysd daemon with a new version
which supports flipping portrait mode 180 degrees. Once the new sysd
is installed you can control the portrait orientation by adding the
following line to the [registry] section of System/dr.ini on your
flash card:
/apps/er/sys/display/flip=true
To return to normal orientation without uninstalling sysd set the
dr.ini setting to false and reboot (hold power switch for 5 seconds).
Before updating to any future version of this mod be sure to uninstall
it first. If something goes horribly wrong you can reflash the
firmware on your reader to remove the modification.