In my module development, I would like to know the LastLogin date of the user.

That way I can display new content since the users last login.

However, the LastLogin always gets updated durring authentication so I never know when the actual LastLogin date was.

Is there some way to get or retain this? 
I know DNN doesn't like session variables, but this is valuable information for a module developer.

Any thoughts?

I was thinking about just adding the last  login to a session variable before DNN changes the value. 
However, I generally don't like to modify the DNN core since I update DNN regularly and I would have to add the code back every upgrade.

Is it worth suggesting that this be added to the Core?

For just one example, in the forms, it would be nice to view posts since last login, like PHPBB and vBulletin let you do.
But we don't have access to the last Login date by the time our Module's execute.

Mitch, thats a pretty good idea, you got my wheels turning thanks...