[web2py] how do get "me" to imporsonate a generic user?

[mart]

Hi,

I would like to make use of the following snippet (something I have
here often enough)

* in controller
db.someTable.user==me)).select()

* in db.py
if auth.is_logged_in():
   me=auth.user.id
else:
   me=None

How do I turn this into something like

if auth.is_logged_in():
    genericUser=auth.user.id

while the user is visiting on THIS page, they can as an option, assume
a generic user's ID to view his stuff (file system resources) but with
stricter permission (like view and download, but not change or delete?

Thanks,

Mart :)