Peter wrote:
After hacking with a small chisel, and probably damaging my good
lindstrom side cutters, and still not getting anything close to what I
would call a technique - I figured I would ask what is a good
technique for removing oval headed nails from floorboards into joints.
I would rather damage the wood as little as possible.

Difficult. Why are you removing the boards (or how many are
you removing)? If you can pull the boards up, the nails will
either pull out, or through. There are ways of pulling up
boards with minimal damage. You could always use a nail
puller - first Google result:

http://www.smithfrancistools.co.uk/nailpull.htm

- although if the lost head ovals have been punched
down the jaws will mark the wood to an extent.