Back in the day, we used to call that "honking."

The technique is to choose a gear that allows you to use the bike as a stair-stepper, simply transferring weight from one pedal to another. And your cadence will be much slower. If you push down on the pedal to a significant amount, you're doing it wrong.

I actually like standing. It stretches out the back, strengthens the arms and core, and just offers a nice change on a long climb. I have a 30 inch gear on all of my bikes save for one, and on that bike, I have to stand up to make it up longer grades. Heck, there are times I've gone a full mile or more standing up.