I've recently found the PhiferReader really helps in holding books since my arms and hands tire. Sometimes I still need to place it on my Levenger laplander lapdesk so I can lie down completely flat. The lapdesk has a firm rather than bean-baggy cushion which is much better for a good supportive surface for reading or working. Levenger does have a lapdesk that will also angle as a bookholder, but at 8.5 lbs, it's too heavy for me to use. The only problem with the Phifer reader? Constantly having to flip back the page holder, which tires my hands and arms and neck when it hurts. But I can read more quickly now and overall have to exert less painful effort.
The laptop cart has the potential to be helpful, though I find the two-sectioned ones can't drop the smaller tray low enough--I'd like document holders or book holders to be even lower so that I can see the pages easily rather than having them poised a foot too high. The middle post for the cart also sags too much for the laptop, meaning I type a little diagonally.
I can write on the laptop with the Levenger lapdesk on my knees or the lapcart positioned above me, but I find it difficult to extract myself from underneath the lapcart--that requires someone else to be around so I can get up since the wheels catch. I am having difficulty finding ways to write that don't tire my arms (lying down with lapcart or lapdesk) or my back/neck (sitting up and working at lapdesk) too much.
What we need are better multi-function tables/carts for work lying down--current models are geared toward people sitting up, though lying down you may need one tray lower. At least there are ledges now on these carts--I was limited to an angled hospital tray when I was growing up, and had to hold books and try to write at the same time.
All of these pieces of equipment help greatly, but I do find myself needing to alternate among them as I tire from using one position or type of exertion. A new page turner will be available in September--before, these things cost thousands of dollars; one of my friends could use one of these and hasn't been able to afford one. It would have to be positioned on something for someone who works lying down--it would be nice if it had a flat base!
Because I'm a big believer in small business enterprises, let me also point out that the inventor of StaticOff posted in the comments here and says to email if you have questions. Thanks for stopping by!