Looking at photos of myself recently is what's spurred me into dieting now... It was a real shocker to see just how much differently I look now than what I look like in my head!! And now I find myself avoiding pictures too.
But like someone else said, I too find that looking back at past photos can be enlightening. I look back at pictures from years ago and think wow, I was so beautiful, and thin! And what's even more than that, I love the memories associated. But I PRECISELY remember looking at those exact same pictures when they were taken and being absolutely disgusted with how fat I looked...it's like I'm not even seeing the same picture! So that's something I try to keep in mind.