As I was putting the finishing touches on an external USB-UART adapter for the TAP-28, one of the adapters I ordered from Ebay arrived. It had been a couple weeks since I had ordered it, so I didn't remember all of its features. It actually has the major features I was designing into my adapter, at a price that can't be beat. It's around US$6, including shipping.
It's called a "USB 2.0 to TTL UART 6PIN Module Serial Converter CP2102". offered by Y & L Cabin. It's a 0.5 * 0.75" board with a CP2102 chip, a USB connector on one end and 6 header pins on the other. Not much to it but everything it needs.
The second picture above shows the connections: Ground, TxD, RxD, RST, and 3.3V or 5V. It will supply either voltage from the USB interface. This of course makes it perfect to power a TAP-28 board equipped with an 18F25K20 to run Amicus code. It's also useful any time you want to have a serial interface to a PC without the need for using the PICKit 2 UART tool. You can use it with any terminal emulator or even interface to it using software that recognizes a COM port.
The picture below shows the interface in use with a TAP-28 board running Amicus code on an 18F25k20. It's powered only by this USB interface. Pretty slick! The LED on the adapter shows that it's connected to the PC and active (i.e., it's been properly enumerated).