Come up with an interesting project, and implement it. Try to come up with something really fun and innovative, but also keep in mind the amount of time that you have to complete it. Prepare a 5-10 minute presentation for the rest of the class to discuss what you will do, describing what sensors you will use, what algorithms you will need, and how long it will take you to implement.
During the official final exam time slot for the course, we'll meet to see the demonstrations of the projects.
If you're looking for inspiration, here are some possibilities from Jennifer Kay's robotics class:
Good luck, and have fun!