Avoiding carpal tunnel / repetitive stress injuries
slackerIII: Things I've done:  -switched the mouse to my left hand 
  -installed WorkRave, actually did what it said
  -switched the caps-lock and ctrl key
  -switched to dvorak
  -use the ergo microsoft keyboard
  -avoid laptops
  -learned to sit up straight and not cross my legs
  -stopped using the mouse scroll wheel

These days I'm trying to pay attention to my keystrokes.  For example, using the right shift to make (){} results in some stressful twisting, so I'm trying to cut that out.If you spend a lot of time coding, try to spend more time with a pencil and paper designing before you hit the keyboard.  That gives you a good break and reduces the amount of typing and deleting you'll do.