Inspiration for classroom activities can be found in so many places, including The Ellen DeGeneres show. I'm not sure how my web browsing led me to videos of The Ellen Show a few weekends ago, but on the right of YouTube page I saw the title, "Ellen and Jennifer Lopez Dance-Off" (click on title to see the video).
True to Ellen's style, she made the Dance-Off look fun, and I started thinking how I could use something similar with my students. While an identical "dance-off" would be fun, it certainly wouldn't be related to the curriculum. However, last weekend when I was planning out the week's activities, I wanted a quick review of how to say s/he was doing something, by using estaba + gerund (ex: estaba nadando, estaba escribiendo, estaba bailando), and I decided now was the time to use a variation of Ellen's activity.
I made the below powerpoint for a fun warm-up, but it would also work great as a brain-break because it is quick and it gets the students up and moving around. The directions for the activity are on the #2 slide below.