I use this one and really like it.
http://www.amazon.com/gp/product/B004TM1JBE
I am able to sit/lay in bed and can type as well as read on it. I like this design better than some of the others.
In other cases the part that will be the inside, flips under to make a stand. That means that the part that will go against the screen is getting all dirty and dusty from the table.
In this version, the part that goes against the screen never touches the table and stays face up. Hope that makes sense.