I got a Fisher Space Pen for Christmas (military version, a whopping $8). I think that a survival situation I imagine would be more urban in nature and temporary. Writing could be neccessary for something...what? I don't know.

For a long term scenario, I would think you could find enough writing instruments around for your needs.

When I'm backpacking (the only time I ever anticipate the chance of a wilderness survival situation), I use a pen a great deal for navigation off trail and note taking.

I suspect note taking is also critical for a medical emergency.

Perhaps it is a convienienc, but I feel naked without a pen. Not really, but hey.