CSSU has provided portrait mode as an experimental feature. This can be enabled by changing the value of forcedrotation from 0 to 1 in /usr/share/hildon-desktop/transitions.ini. D-livil's transition tuner can also be used as a graphical interface for this purpose. This wiki page gives the status of portrait mode support in various apps. At present all apps do not display correctly in portrait mode. Hence, future updates of CSSU will have rotation based on a WHITELIST. ie, only applications mentioned in the whitelist will rotate, while the rest remains without rotation. Please help us keep the wiki page updated so as to get a comprehensive whitelist for rotation.