Does Age Matter?

I had breakfast with a group of girls this morning and one girl just started dating a guy many years younger than her. We started discussing what everyone thought of dating a much younger guy. My personal opinion has completely changed over the last few years. I used to always assume I'd date and marry someone older, and would NEVER even consider dating someone younger. Now though, my joke has been I'll meet him at his dorm as long as he treats me nice. Seriously, as long as he acts like a man and can take charge, I don't care how old he is. So what do you all think about this? Would you date someone younger? Significantly younger? What about significantly older? What's your limit?