Yeah, it would mean setting up nat on pc2 so that pc1 and pc3 could talk. .. but yeah. The best way to do it is to grab a cheap hub for <$50 and hook up each pc to the hub and setup each pc with appropriate IP's
For example, here is an example IP strategy
192.168.0.1 -> PC1
192.168.0.2 -> PC2
192.168.0.3 -> PC3
And each pc would of course get jacked into the hub with a regular cable (no crossover).