Here is another PAT idea from Charlotte Meyer on the FLTeach listserv. She read about it in her Avancemos textbook, so you might already be familiar with it. Who knows :) Anyway, I like it because it is simple, takes no preparation, and could be played for a short amount of time (it's always nice to have filler games!).
Students stand in a circle. In order, they count aloud the numbers 1-10. Whoever says the number 10 is out and must sit down. The catch is that students are allowed to say 1, 2, or 3 numbers when it is their turn: they could say dos, or dos-tres, or dos-tres-cuatro.
Once your students have down the numbers 1-10, it seems that it would be wise to change how you count: either 11-20, 21-30, 10-100 by 10's, 5-50 by 5's, 100-1000 by 100's, etc.