LilyPad Programmer or “FTDI Basic Breakout Board”
Attach one end of this board to your LilyPad and the other end to a mini USB cable to program your LilyPad. This board allows your LilyPad board to communicate with the Arduino software via a USB port on your computer. When a program is being uploaded, you’ll notice that LEDs on this board will flicker on and off, a sign that communication is going well.
The LilyPad programmer is a version of SparkFun’s FTDI Basic Breakout board. This board is the same as the other (red) SparkFun boards, except that it’s thin and purple.
Purchase from Sparkfun
To install the FTDI drivers: see tutorial here