I learned about what looks to be a great resource for high school kids today, www.meritaid.com. The vast majority of merit-based scholarships come from the colleges themselves (as opposed to outside scholarships that come from companies, organizations, private donors, etc.). And this website seems to be culling that information together so that a student can search for schools and research the scholarships that are available. You can even create a profile that will generate a list of colleges with potential merit aid that match your profile.
I would still argue that visiting the schools' individual websites is the only way to be sure you know about all of the scholarships they offer, but you could use this site as a way to narrow down your search.
Thanks to Mary Beth Kravets, a high school counselor and author of this fantastic college guide for students with learning disabilities, for sharing this.