Shmoop and Zinch have combined to offer a $3000 scholarship to US students. To enter the contest students simply need to complete this form by May 31st.
Zinch is a service that helps match students to scholarship opportunities. I don't have much experience with it, but it looks promising. Shmoop provides many fantastic online study guides for high school students. I've written about Shmoop since their launch and they've continued to improve their offerings ever since.