Do you let cats sleep in your bed?

My cat pretty much sleeps where he wants to, including my bed. He tends to hang out on the couch when I am there, or with the kids when they are here, but at bedtime he is in my bed. Every night. And he sleeps where ever he wants, mostly on the other pillow next to my head, but sometimes at the end of the bed. I have never rolled over on my cat in my sleep but I can promise he would move out of the way very quickly if I did. I have accidentally stepped on his tail a couple of times, but I catch myself when I feel it under my foot, but he moves very quickly.