Objects in Session variables ?

Hello, In my current PHP4 project, I have a "User" class, amongst a couple of other classes. What I'd like to is: when the user logs on to the site, store his personal "User" object in a session variable so that I can easily access all of his information from any page without having to requery the database to get that information. Is this possible, e.g. can one simply session_register() an instance of a PHP class, even if I'll lose the methods and only keep the member variables ? Thanks !