Building an antanna for OTA viewing

Here's a challenge we've been wanting to take on for a while, but we never got around to doing it. Now that we have time, we are wanting to build a multidirectional antanna for picking up OTA HDTV.

We currently have a standard outside antanna mounted up on the roof, really high up in the air. We get ~30 channels now, but we have to constantly turn it, and it's still sometimes choppy.

This is what I've seen at about 2 or 3 websites and on a tv show:
http://uhfhdtvantenna.blogspot.com/

But I'm pretty sure you would still have to turn this, wouldn't you? That would mean more work, and we are wanting something you don't have to turn at all.

I would really appriciate any tips.