My family has been getting into Super Paper Mario for the Wii in a big way.
This application came about as a result of us trying to do the "Cards Quest" (You have to collect 256 different cards). It is difficult to figure out what you have and what you need.
A normal person would just use a paper and pencil. A geek would write a database application.
Technologies used in this Java app: Tomcat 5.5, Spring Framework, MySQL, JavaScript and AJAX.