I'm doing my open class on this lesson, so here are some of my materials.
There's a ppt for low level speaking (I have done it with my C class and they love it) and also a ppt for high level speaking (my open class). I cobbled it together from various other ppts on this thread, but added in my own pictures and made the structure a bit clearer.
For the high level class, you need to make at least 4 sets of riddle cards for them to collect. You can copy the riddles from the ppt. I don't have a lesson plan for the lower level class (it's pretty obvious from the ppt) but I do have one for the high level class.
In the low level speaking class, I recommend you change the 'That's great' pictures to whichever movie is currently the most bestest in the world (to your students). The example in the book is for Harry Potter. I changed it to Iron Man 3. These things date quickly so do check it over before you put your kids to sleep.