You could modify the user action (in controller) to customize the form
returned by the auth() call. So you would be able to set a default
value to the "remember" checkbox input and hide it (by passing the
attribute _style="display:none;").
Maybe this is not the best approach (deforming the helper output).
There is got to be a simpler way of customization of the standard
scaffolding authentication service that i missed. Or it could be added
as a project task.
Section 8.3.6 covers customization with auth object settings
There is an auth settings attribute called long_expiration (specified
in seconds) wich controls the user's session expiration time.
User session expiration is treated here:
http://groups.google.com/group/web2py/browse_thread/thread/e70e186d960d7163/c33cd28bb4e37bf4
Have you tried setting a long (in seconds) auth.settings.expiration
value?