I suggest getting involved with local in school organizations to help register voters. I mean I know blood drives are a staple of high school life, so why can't voter registration drives be as well? You could easily get donations from local political parties to hold the drives, and use that money to buy some jazzy pins (or being craftsters- make your own).
My personal suggestion would be Key Club. I know the New York District is trying to get all the clubs to hold these drives- it's easy! Haha, and you could incorporate a bake-sale. One free "baked item" if you register. I know tons of hungry teenagers would love that. Haha. Also, try your school's student council program. They are encouraging leadership, and a lot of times the structure of the program mocks that of the US. So get them involved. =-) And I bet you could even speak to local politicians to speak at school, encouraging kids to vote.