How Safe is Codeigniter Sessions

[eluser]keevitaja[/eluser]
[quote author="WanWizard" date="1349160958"]
The idea behind the token store is that you can detect that the remember_me cookie was stolen and used by someone else because the login by the hacker has caused the token to rotate, so your original cookie has a valid token, but not the last one issued.
[/quote]

will this work, if "remember me" can be set from more than one computer?

and which one is better approach:

- store users id in the cookie
- store users username in the cookie
- store the id from the "remember me" table

and ofcause hash and token as well.