I've been having trouble with my neck since a training injury in early 2012 left me with nasty headaches that took a few physio trips to clear up. Since then I've been battling with my naturally slouchy posture to keep myself relatively pain free.
I have a computer chair I really like at home but my posture still tends to suck. I've played around with creating a DIY standing desk (ie chocking up my regular desk with lengths of wood) but discovered I just can't stand around for hours on end comfortably.
Today I decided to do something about the situation by creating a lap desk for my keyboard and mouse that attached to my chair. Well, originally it was just a lap desk, but when I discovered how front-heavy the MDF I decided to use for the surface was I had to work out a way of attaching it to my chair.
I ended up with a pretty rough prototype (ie something I'll use until it falls apart, I get a new chair or someone comments on how ugly it is) that I'm quite happy with. It attaches to the arms on my chair nicely, is at a really comfortable height, and things don't slide off it like I worried that they would (I bought some wood strips just in case to put at the bottom so things wouldn't slide off).
One of the immediate downsides is that it makes it more difficult for one of my cats to get onto my lap while I'm at the computer. She manages but it's obviously only because she is expending Great Effort to do so.
Photos and stuff are over in Things.