Wow!! My answer about this has certainly changed. It still doesn't offend me, but the question definitely annoys me now. Some people seem to think this question is the same thing as "What time is it?" I've gotten to the point where I'm like, "Why the eff do you care? Why is this important? I don't even know you, so why do you feel like it's okay to ask me about my racial background?" It would be one thing if we were having a conversation about heritage/ethnicities, but it's just a nosy question.