Legend has it if you press "F" during this boss battle it accelerates you to the point where you can pass the Yeti. While it definitely does accelerate you, I cannot personally confirm that you can actually beat the Yeti but that is what they say. That is what this comic refers to. Update: I have outrun 'em for quite some time but never reached any kind of "end". :)
So, make your very own 'F' key pendant symbolizing...anything, really. Cheating death. Overcoming obstacles in life. Your 1337 gaming skillz. Undying affection, maybe? Whatever.
Some may say "Congratulations on drilling a hole in an F key." To which I say, Bah humbug! There is elegance in simplicity. Any designer worth his/her salt will tell you that complexity does not a good design make. Besides, half the fun is that it doesn't look like much to write home about unless you know about SkiFree/the comic.
(If you want to learn more about the game, or download it (runs in windows and works fine in wine), please see http://ski.ihoc.net/. If that doesn't work, try the google cached version. Legal downloads, yay!)
Step 1: Materials & tools
An 'F' key (duh).
Cord/wire to string it on (I used SoftTouch nylon beading wire).
Source of fire (I just lit a candle).
Small-diameter, sharp-tipped metal implement (I used a special xacto attachment).
Crimping pliers (I mislaid mine so I just used regular small pliers. It works, but be warned it's a bit trickier and you don't quite get the nice crimp you do from using the specialized pliers.)