Diversity in YA Fiction is a fantastic website (and book tour) created by two authors, Cindy Pon and Malinda Lo, to celebrate diverse stories in YA. They always have wonderful information on their site, and it's a great go-to for YA titles with diverse characters that you may not hear about otherwise.
This summer they created The Summer 2011 Diversify Your Reading Challenge
"This summer, we’re challenging readers to read books that feature a diverse world, to read beyond their comfort zones, and to just plain dive into some wonderful stories."
I think this it's always a good idea to push ourselves to read more diverse characters and stories because you just never know which books are going to be the ones that speak to you. Especially for me as a teacher, I feel it's important to read these so that I know what's out there for my students that may need/want to read about various themes.
I hope you'll consider joining the challenge!