Casting off with circular needles

I am knitting a hat from the crown to the rim on circular needles, and want to know the technique for “binding off” while on circular needles. I cannot find any video demonstrating this method. Does anyone know of any links to a video, or easy to follow verbal directions?

There is no difference I’ve ever heard of between binding off on a circ and binding off on any other type of needle.

Bind off the same way you always do. However when binding off the edge of a hat like that you need a stretchy bind off. Here’s some. I’ve done the k2tog and it was pretty stretchy. Some people say the sewn bind off is the stretchiest, but I haven’t tried that one yet.
http://www.knitty.com/ISSUEsummer06/FEATsum06TT.html

Here is a tutorial for dealing with that last stitch when binding off in the round. I haven’t tried this, but I will next time!!
http://www.woolywonder.com/freebies/cufftutorial/

Same as a regular BO, but the last stitch is going to appear a row higher than the first one. What I do - with the last loop on the right needle, pick up a stitch in the center of the first bound off st and pass the loop over it. Then bring the tail through and weave in the ends. And yeah, it helps to have a stretchy BO, so use one that Jan suggests, or a needle 2 sizes larger.