Simple presentation, with color and animation, that I've entitled "Name That Verb!". Each slide lists a situation (i.e. describing location, hair color, nationality, etc) and learners have to decide whether you would use SER or ESTAR. After the teacher clicks to reveal the answer, an example sentence appears as well. I have students use a sign that says SER on one side and ESTAR on the other and the activity works well as a quick review.