saw this once in Colorado years ago. haven't seen anything like it since.

http://antwrp.gsfc.nasa.gov/apod/astropix.html

We have been getting clouds that look that quite a bit the last few days.  Never noticed before.  The clouds look like oreo cookies.

Very cool picture.

I've never seen clouds like that.  Cool pic

Clouds are cool

http://www.darkroastedblend.com/2007/04/mammatus-lenticular-other-extreme.html

I wouldn't have been around long enough to photograph that if it were me.  I'd be RUNNIN.

That's mountain is right out my back window.  I wonder what day that was, because I don't recall seeing that.  But then again, that's a different angle, and I think I was right under them.