how to properly cache menus and other parts of a web page

[eluser]tonanbarbarian[/eluser]
i dont know if there is a "proper" way to do this
one suggestion though would be to use sessions.
When the person first comes to the site either build the menu, or at the least grab all of the menu data and store it in the session.
If their login status changes i.e. they login or logout, you recalculate.
this way you only rebuild the menu when you need to for each user