NOTE: this page is incomplete. Pester igutek if you want more info. He claims to have partially complete eagle files, and a hacked together ethernet stack that compiles, but does not run.. maybe.
This page contains information about progress on a simple ethernet board based on the PIC18F26K80. Development has come to a standstill due to all kinds of nightmares withe PIC stack.
http://ww1.microchip.com/downloads/en/DeviceDoc/39977c.pdf PIC18F26K80 Parts: http://www.sparkfun.com/products/8534 5mm ferrite beads 25.000 MHz oscillator 74ACT125