µFTDI is a redesign of the SparkFun FTDI Cable optimzed for size. This version is identical to the SparkFun one, and works exactly the same, except the board is 0.5 square inch and uses smaller components. This board is perfect for embedding in any project.
If you plan on making a small quantity of these, take a look at the DorkbotPDX PCB Order. This board will cost 2$ for 3 copies. The components can be purchased for about 6,50$ and the LEDs and accompanying resistors are optional.
The 3-way solder jumper on the back (near the USB connector) does not have a default connection, the center lead must be soldered either side to select 3.3v or 5v operation. The photo below shows the solder jumper configured for 3.3v operation. The silkscreen does not quite show the pin 1 of the FTDI IC, so make sure it is oriented as shown in the photo below (pin 1 is in the lower right corner).