Forms Data Controls :: Gridview Two Way Binding And Custom Objects?

I have been reading alot about this and for some reason I am just not able to grasp the concept. Hopefully someone here can enlighten me.As an example situation I have a collection of strongly typed User objects that represent a database table, and some properties that represent its columns: UserID(PK), Username,FirstName,LastName, etc..Here are some of my requirements/goals:1. Users/Objects needs to be bound to the gridview programatically.2. I do not want to update the database right away, I only want the underlying collection to be updated. I would like to call the database update method myself when I am ready.
3. I do not want the primary key stored on the client side.Summary:So I bind a List<Users> to a gridview with the appropriate bound fields set up, I exlude bound fields such as primary key because I don't want it being changed/hacked by the client side. When I edit and update a row it is saved back to the collection of objects. I will iterate through the objects manually at a later time and commit them to database.

Questions:1. Can I cast a gridview row directly back to my object, in the RowUpdating or RowUpdated events? I am assuming I can't... So....2. How can I reference back my original collection if the gridview does not contain a primary key?3. Where do I store my collection, should it be in Session or should I recreate it on each postback?Sorry if any of this is confusing, let me know if you need clarification.