Remember me?

[eluser]tommyadey[/eluser]
Remember me feature is meant for logging a user in automatically even when the session isn't active. It doesn't get easier than that, that is, if you care for security.
You could leave the database out,yes, but you still have to do most of the thing's i mentioned eg the cookie login function.
Oh and it depends on how big your project is,you can easily write the cookie login function on top of the controller you want it in and you only need the database if you need to keep track of the cookies being set. A user can log in on many computers, so you might want to let them know what computer they are still active on and if they want to delete/log out some. Just like how facebook does it.