My impression is that RSI differs from person to person, which means the solution differs from person to person depending on what is strained. For some, a new keyboard layout fixes the problem. For others, simply changing to a less strenuous editor like Vim helps.
cruising around work and checking people's setups...
The overwhelming majority do nothing. Many folks do everything on their laptop (not possible to be ergonomic) and most desktops lack any sort of ergonomic planning (monitors off center, no wrist rests, etc)
There's a lot of low hanging fruit out there.
The wrist rest should keep your wrists straight and keep them off the cold desk and its sharp edges.
Posture should keep your head balanced over your neck, not holding it forward or backwards. The monitor height should support this, and it should be straight in front of you. Your shoulders should be relaxed and your elbows should be around 90 degrees to help your wrists.
By the way, laptops are not ergonomic. There are no OSHA approved laptops.