During a demo at SXSW, the BlackBerry PlayBook was finally shown off in detail using portrait mode. We have seen PlayBook in portrait before, but not to this extent. The transition between landscape and portrait looks to be quite fast, and smooth as silk. It's great to see RIM's latest build for PlayBook so polished, especially so close to the device finally launching. Skip to 5:45 on the video to see the PlayBook in action using portrait mode.