Adam, I haven't worked much with the Touch plug-in, but try the following and you will see the actions and methods you need to use:
1. Create a new project
2. In the layout, add the Touch plug-in
3. In the layout, add a sprite
4. In the event sheet, add an event: Touch:Device orientation is supported. This is a condition which checks to make sure that device orientation is supported. If it is, then the action will be executed.
5. Add an action, and select your sprite
6. Under the Size & Position section, select Set X
7. When the prompt comes up, go to the Objects with expressions window, and select Touch
Under the Orientation & Motion section, you will see the Acceleration methods. This should get you started. There are many others on the forums who will be able to help you with the specifics regarding the methods and the math involved.
Don't see the fnords and they won't eat you!