Tool: PLEX, another deck of inspiration cards
PLEX is a deck of cards helping designers to be inspired about playful scenarios, used in the PLEX Brainstorming and PLEX Scenario generation techniques. The cards were created to communicate the 22 categories of the Playful Experiences (PLEX) framework to designers, researchers and other stakeholders who wish to design for playfulness.
Download the cards and the guidelines at http://www.funkydesignspaces.com/plex/
See also my other blog post about the IDEO cards.