How can I disable auto-rotate on my phone?
if you need easy access to it then 

Menu -> Settings -> CyanogenMod settings -> Display -> Interface -> Notification power widget - > Widget buttons -> Toggle Orientation 

will add a widget on the notification menu that lets you enable or disable rotation. just about the only time it seems useful is if you are lying on your side and you want the phone to stay in landscape, but it sure is convenient for that.