Let me try and help you. Lazyman's link only angles down, it doesn't lower. I don't know of any that lower, but that doesn't mean it doesn't exist.
Now, to the point of my post. I have an LG 55LH90. I had it wall mounted above my fireplace mantle (before the LG, I had a 47" Vizio wall mounted in the same spot). It was on a tilt mount (aimed about 15 degrees down). We watched TV and played video games on it for quite a few months that way.
The mantle is about 5 1/2 feet high and the center
of the TV, when on the wall mount, ended up being around 7 feet high.
We recently rearranged the living room and got this: http://www.samsclub.com/shopping/nav...=5&item=411874
WORLD OF DIFFERENCE!!!!
Not only does the picture on the TV look better because I'm eye level, but when the TV was mounted above the mantle, our necks would get sore and our eyes would dry out. I read that looking up at the TV for an extended period doesn't give the tears in your eyes the ability to flow properly. It sounded like horse-pucky at the time, but I believe it now!
In addition to all that, the TV looks bigger now. I'm basically the same distance away, but since I'm not looking at it with that extreme angle, it seems bigger.
In all, the fireplace mantle idea was a good concept....it gave us some more room in the living room and got the TV out of the way, but it made it about 60% less enjoyable.
My wife and I are both SO happy we decided to move the TV down to eye level.
Good luck and let me know how it works out.