Running Ubuntu 9.04 onan Aspire One. Under System Preference Display, you have the rotation option of left, right and upside down.

It occured to me that for some documents using a .pdf reader, it would be more convenient for reading purposes to orient the page to the left for example.

This is a little strange. But it is usable, until I try to use the track pad. The X and Y moves on the track pad remain unchanged. So now to move up, I need to drag to the right, and to move down, drag to the left and to drag left I drag down, and to moveright I drag up. Very disorienting.

So I figured if I can rotate the screen, surely I should be able to rotate the track pad. But no such option exists.

Do I need to rewrite a mouse driver and rebuild the kernel to get this to work? Or is this simply an item for which there is documentation that I haven't read yet?

Some suggestions:
1. use a usb mouse. (small ones exist for laptops etc.)
2. mod the touch pad by removing it and installing it in a different orientation. (probably not practical unless you intend using it that way permanently)

it might be possible to find a software solution that doesn't require rewriting the mouse driver.

Ha, Ha, funny, funny.

Actually I have a usb track ball I much prefer to the trackpad. But it just seems awfully strange to me that the capability of swapping the screen is so prominent, and the corresponding pointer control to go with it is so hard to find. Did a yahoo search, and the top ten responses included this post, and not much else that was relevant. Yahoo search got messed up with lastest set of changes. I suspect it is the Microsoft influence.

Searching the Ubuntu forums, I see some references to modifying xorg.conf, which then requires you to restart x to make work. However I find no trackpad reference under /etc/X11/xorg.conf, (See Below), so I would have to assume stuff has been moved elsewhere.

Note, this issue seems to be built in for the Apple iPhone, where simply re-orienting the phone, switches between x and y, automatically corrects the touch screen orientation. (Think about it, it does get corrected.)

With normal laptops, changing the screen orientation is awkward because they are so unwieldy, but the netbooks are a smaller package, and it is not as unreasonable as one might think.

# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "Device"
Identifier "Configured Video Device"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection

First, I do not believe this is supposed to change, second, connect an external mouse.

Actually, I played around a bit and, while I haven't found a solution, I've found another use-case for it. when using gthumb on a 1024x600 screen, it only displays a thin sliver of the image you're working with. By turning the screen left, you get a much better work area on a 600x1024 screen. So maybe we should ask the good folks at Canonical to implement a solution in their next release of UNR.
I'm a little concerned that modding the mouse driver would have the undesirable effect of messing up any other trackball/mouse input device that you might want to use with it.
On a related issue, I was thinking about building a new case design for my Aspire One. By adding a touch-screen and hiding the keyboard in a slide-out, I could get a very interesting MID (Mobile Internet Device). A similar product would probably cost twice what the Aspire One costs. And by building my own case, I'd be able to make room for several extra SSD or HDD storage drives.
Just a thought.

Theoretically, it should be consistent for any mouse device.

For example, if you rotate the screen to the left, then the left side of your laptop becomes the top. You turn your laptop so the right side is at the bottom. When you move your finger what was to the left on the trackpad, it moves the mouse pointer up.

On a mouse, to get it to work, you are turning the mouse ninety degrees clockwise. Then you move the mouse away from you, it is moving the pointer up, and your left mouse button is now at the "top" of the mouse.

Sounds slick. Will you post here if you decide to do it? I'd like to know if you do.

You still have to rotate the mouse, and your left button is no longer under your thumb.

Are you sure about that? I believe using an external mouse will work fine.

However, I'd like to know how to rotate the touchpad input also.

an external mouse should work since the touchpad is technically still working correctly. It's just that the touchpad is fixed in position. Yes, an external mouse would be turned ninety degrees, but so is the screen so they would both agree with each other. The touch pad, however, can't be turned to agree with the screen.