You can determine what COM port an FTDI device enumerated to by opening the Mac OS X's 'System Information' in Lion or later (or 'System Profiler' in Snow Leopard and earlier versions of Mac OS). Plug it back in, and select the device that has now reappeared. The device you unplugged should no longer be listed. To figure out which device is which, look under the Arduino IDE's 'Serial Port' menu.

Note: If you have more than one FTDI device plugged in to your computer at the same time, all of the devices will show up in the Arduino IDE's Serial Port menu and device manager. Now that you know why the FTDI Basic is important and what products it is used for, let's learn how to install the drivers. Newer versions of Arduino boards, such as the Uno, use a different communication IC, and they will not be covered in this tutorial. For a complete list of all Arduino boards, check out this page. If you have one of these older versions, you'll want to use the FDTI drivers as well. The Arduino Diecimila and Duemilanove main boards along with the original Arduino Mega all use the FT232RL IC. There are also some legacy Arduino boards that use the FT232RL.

Protosnap - LilyPad Development Board Simple.

Here is a list of some SparkFun products that require the use of an FTDI Basic, come with an FTDI Basic, or have an FT232RL chip on board:

Megasync not opening mac