What makes the 18F2x5x chips special is the USB functionality built in. This allows them to be powered directly from a USB port, as well as being able to communicate with a computer. Also, with the slightly modified Microchip USB Bootloader, the PIC can be programmed by anyone without a dedicated PIC Programmer.

To program the PIC, I used the JDM style serial programmer available from Sparkfun, although I believe they are sold out at present. To program it, I used PICPgm, or WinPIC.

Bootloader HEX file

MPLAB Project Files

Microchip USB Page
Microchip Bootloader Software
Instructions

 

Many thanks to Brian Schmalz, creator of the USB Bit Whacker for his help.