i love ergonomic keyboards and chairs. They're designed to minimize muscle strain, and i think that's an important issue today!
wow, tell me more 
Well for a good keyboard, I use one in the shape of a V so that both my hands can be at an angle, and it's more natural. No more muscle strain!
when did this trend start?
Well there was a contoured keyboard developed in 1977 that changed the arrangement of the keys to shoulder width!
Which company have the best of these ?
I believe it was called Maltron. In their configuration you didn't really need to move your arms or wrists.