My mind is reeling over the possibilities of this module. ... err ah.. my mind is really reeling over the abuses this modules could enable me to do. Wow... mind explodes.
Dynamic Field is a CCK field that returns a textarea where you can enter custom PHP code.
http://drupal.org/project/dynamicfield
So, this enabled you to really neat hacks via PHP like, if this field is X then do Y. ON the flip side, you could embed a view into a field OR run a SQL Query.