Cameras and Lenses
Military (or Thumbs Up) Grip: As Seen On TV
I was watching a BBC documentary recently "James May on the Moon"
http://en.wikipedia.org/wiki/James_May_on_the_Moon
For part of the show they go to Beale Air Force Base in California (because that's where the U2 fly from). There is a sequence that shows a U2 landing and in amongst that there are lot of shots in the control tower with carious controllers squinting through various porros at aircraft around the airfield.
Most of them use a conventional fingertip grip (the "usual porro" grip with a seagull stance) but one USAF controller uses the US Armed Forces approved Military (or "Thumbs Up") Grip. This is the first time I've seen someone (other than me) doing this.
I had to grab a screenshot 
Hi, after reading about this grip somewhere in the Forum, I tried it a couple of times (with my roof bin).
What I like about it is that the thumbs can be used to block off sunlight from the side between eyepiece and eye and that it is indeed somewhat more stable. However as the index is not ideally placed on the focus wheel, quick and precise focusing does not work with this grip (not an issue for military use I guess).
So I only use it sometimes when haveing a prolonged look on a bird that is so kind not to fly away too quickly...