It's fun and profitable to sell things on ebay. I sold a mechanical pencil once. People will buy anything. Your assignment is to use what you know about good photographic composition, lighting and GIMP tools to create a great photo for ebay. If you actually bring in something to sell and will donate the funds to our class, I'll schedule time for a pizza party. So, what do you have that you can photograph?
Here are a few sites with ebay photo tips: