Left-handed users may want to check out the thread Canola2 on Portrait Mode. They got this to work by using XRandR (X Resize and Rotate extension) to rotate the entire X-Windows environment by 90 degrees. XRandR can also rotate 180 degrees, but you'd still need to remap the up/down left/right hardware buttons.

Perhaps if more people voted +1 for the xrandr kernel mod in the Canola thread, it might get incorporated into a future kernel update.