node_data
This module makes it easy to add fields to custom node types. Think of it as flexinode (or CCK) for coders. That is, if you're going to create a module and define your node type in PHP, this module makes it easy to add various fields to the node type. It defines a generic field structure in the database, so your module does not have to create its own database tables. Simply add fields to your node form, using a naming convention, and fields will automatically be inserted, updated, deleted and loaded at the proper times.
Useful for rapid prototyping. As efficient as flexinode in a production environment. But the very best modules would not use this, they'd create tables specific to the data being stored.
You can find node_data in my drupal sandbox.

