When I was heavily involved in robotics, I used Byron Jeff's Trivial Low Voltage Programmer to program Microchip PIC chips. It was certainly simple to build and it worked effectively. While building the VK3BHR LC Meter Project - MK.II, I needed to program a 16F628 microcontroller with the LC meter software. I decided to build Byron Jeff's Trivial High Voltage Programmer, as it could program a PIC device that had the security bit set. In order to provide the programming voltage (13 volts), I used the +5V to +13V Converter found on Roman Black's web site.
The file THVP.pdf contains a schematic of the programmer exported from EagleCAD. I did not make a PCB for the programmer, choosing to use point-to-point wiring on a protoboard. This was mounted inside an Altoids tin. I created a programming guide using OpenOffice Draw to remind the user (me) how to use the programmer and set it up for different PIC chips. The guide was printed and glue into the inside of the lid of the Altoids tin. A PDF of the guide is in the file PIC_Programmer_Guide.pdf.
Here is photo of the completed programmer with data (printer port) and power (USB).