Acratech is now shipping a nodal rail. I have had it for the last week or so, and I can say that this is to date the best option I have found to shoot from the nodal point. Most setup's that I have used are simply to big and bulky, and/or flimsy to make it easy to keep the camera in position. But with this nodal rail I am able to quickly place the rail in its predefined place on my ball head find the level point and shoot away. Really the only weakness is if you want to shoot vertically you need another tool such as RRS L bracket. But all in all if you want a work tool to shoot at the nodal point than I think that this is the way to go. (And trust me I have tried a lot of options to get the nodal point with the 7-14mm at 7mm, and this is the simplest way to do it that I have found)
The thing that I really like is once you have found your nodal point you have the adjustable guides which you can lock into place. The lazer etch detail is very nice. All in all so far this is turning out to be a great product.
I will post a couple examples later, but a fun product. The cost is $200.00.
Here is one example in our little backyard - Tough place to shoot, the ground is on a slight hill, and sun was setting.