As craft supplies become more and more sophisticated there are a number of small projects to help brand your science fiction or literary convention.  The goal is to come up with fun projects that promote the convention as well as make people remember the name and want to attend.  Will a cool project do this by itself?  No.  But it will differentiate your convention from others and show potential attendees the fun that can be had at your event.  Best of all, projects get people involved with planning something they feel a deeper connection to.