Single Sign-In Procedure?

Hi,

I would like to know how to implement Single Sign On/In (SSI) for asp.net web applications or websites.

Using .net passport is too expensive and microsoft doesnt support the sdk's development anymore.

What are the general steps used to create Single Sign On/In facilities?

Are there any links which describe how to implement the SSI feature?
I've found a few sites but would like to read up more :)http://www.codeguru.com/forum/showthread.php?p=1383477#post1383477
Alright, thanks for the link!

I'm going to try them out as they look quite useful :)