It gives a reasonably stretchy bind off finish, too. I like this and I also like the crochet bind off.
shows how to do it. It is the fastest bind off I have found.
From the Sprial Staircase Shawl pattern cast off loosely as follows:
K2, *K2tog, use left needle to slip stitch back onto it with needles pointing the same way, rep from * to end. Pull yarn through last st.
I will be teaching this easy bind off in the future.