Using GtkTreeView: Proxy classes and lazy instantiation

The technique of using proxy classes as items in a list model applied to GtkTreeView gives you for instance the possibility of displaying list of many email subjects whilst mostly instantiating only inexpensive stub objects to represent them, rather than real header objects; something of immense value for memory-constrained scenarios of embedded devices and similar.
You can find its explained here. A sample e-mail application that could use it is osso-email. Follow the link for more information.

Edit: unbuzzworded :-p