My hair is about down to my hips, and it's thick and heavy. I'm used to it, though; I barely even notice the weight unless it's wet. But it's probably screwing up my shoulders and neck. I went to get a massage once, and the masseuse suggested that I get my hair cut so I wouldn't be putting so much strain on my neck. X)
My current goal is to get my hair longer than I've ever had it before, and then shorter than I've ever had it before. I've already reached the "longer" point; now I just have to get up the courage to chop it all off and donate it to Locks of Love.