Well, for RSI a good light switch helps but is usually not enough. You need to change the hand positioning as well, which is were ergo keyboards come in. I consider the Kinesis one of the very best ergo keyboards in the world. It terms of value it's clearly the best. There are some others like the maltron, uTron, datahand, but cost double or triple the Kinesis price.
Not only it helps with RSI, the layout is so intuitive, you never even have to look at it. Mine lives on a keyboard tray under my desk, I don't see it while typing, and I was not much of a touch typist until I got it, but the key locations are so predictable, within weeks I could touch type all letters/numbers/symbols, basically everything except function keys. It's like my brain is connected to the USB port, that's how intuitive this keyboard is. I never had this feeling as a computer professional in the years before I got the Kinesis (around 2004).
I wish I had bought one much earlier than I did, it would help both my productivity and my hands.
It's a also a beauty, especially spiced up. Here's a painted one off the net. Mine is the checkered one further below.
