Self portrait arm for cameras? How do you use them? Timer only?

Just recently I've seen these metal arms that you use to take a self portrait with. They have a head on them that you can screw your camera into just like a tripod. My question is that at first they seem like a cool idea, but the more I thought about it the more I wondered how they would work. Setting a timer is kind of a pain, and some of my cameras don't even have timers. Are there any out there that have a shutter release on on the handle like a tripod?