Sometimes when I'm reading an article or ebook I'd prefer to have my notebook's 1280 pixels in height rather than width. While most display drivers are capable of handling that task, they don't do anything about the orientation of the touchpad. My brain's on-the-fly directional translation gizmo isn't always reliable, so a single application is a better solution for me.
EeeRotate (link via Google Translate) is a handy little freeware app that combines two previous free efforts - iRotate, which handles the screen and SakasaMouse, which takes care of the touchpad. Launch Eeerotate, and you can quickly flip your screen clockwise or counter-clockwise by pressing ctrl + alt + right (or left, respectively).
There's not much to see, as you can tell from the screenshot - the app just gets out of your way and does what it needs to do.
Eeerotate runs on just about any version of Windows, XP or newer, including 64-bit builds.