I guess it's a good resource as it doesn't take a lot time if you use just one card every class.
How it works.
Choose 1 card from the set. It has 6 descriptions (clue-statements) of an object. Your students are supposed to guess what this thing is.
You give them the first clue:
1. I hate the heat.
Students: " Are you a snowman? " - "No." Other questions of the kind.
When there're no more ideas you give the second clue:
2. I'm very good for you.
Students: "Are you a vitamin?" -"No." Blah-blah-blah.
3. I come from an animal.
Plenty of ready-made clues here http://dl.dropbox.com/u/4392166/Methodology/6-clues.doc