In the Midnight session I ran this past weekend, the party wanted to rescue a resistance agent who had been captured and was being taken to be interrogated. The party caught up to the group of orcs escorting the prisoner after they had made camp. One PC decided that he would work around to the far side of the camp, "stumble upon" the orcs, and run away, hoping to lure several of the orcs away from the camp so the others could pull off the rescue.
Only one of the orcs gave immediate chase (two others moved a ways away, but thought they might be running into a trap, so they stopped). As the PC and the orc kept moving their speed factors, they just kept pace with each other, so I decided to fudge up some rules on the spot. The player and orc both rolled d20 each round, added their Con bonus and compared numbers. For every 5 points difference, 5 ft was gained or lost. Over several rounds, the two kept about the same pace, 5 gained, 5 lost. Then on two consecutive rounds the player rolled a 1 while the orc rolled a 20 and a 19. Seeing that the orc was catchign up to him, the player stopped to face the single orc. The orc completed his move as a charge, hit and ended up dropping the PC to bleed out in the snow. Meanwhile a couple of hundred yards away, the rest of the party, who has no idea what has happened to their comrade, has rescued the agent and taken off in the opposite direction.
It was fun, and the fudged up rules worked ok, but I will definitely check out this PDF.