You can find USB/Serial modules that can plug onto cards - price is comparable to buying all the bits and you don't have to mess with the really small FT232RL chip.
mikroe483 at mouser.com
http://www.mouser.com/ProductDetail/mikroElektronika/MIKROE-483/?qs=%2fha2pyFadugsEwyLV5fFyIWdPbushEDhRSvnBE0ODG8%3d
or, mangle an e-bay solution onto a board.