Name=="Future Technology Devices International,Ltd",SUBSYSTEMS=="usb", ATTRS{idProduct}=="6011", ATTRS{idVendor}=="0403", SYMLINK="Ketan%b", KERNEL=="ttyUSB[0-15]*", MODE="0666", SYMLINK+="ttyUSB1",

ls -l /dev/K*
lrwxrwxrwx 1 root root 7 2013-01-08 15:09 /dev/Ketan-8.1 -> ttyUSB1
lrwxrwxrwx 1 root root 7 2013-01-08 15:09 /dev/Ketan-8.2 -> ttyUSB5
lrwxrwxrwx 1 root root 8 2013-01-08 15:09 /dev/Ketan-8.3 -> ttyUSB11
lrwxrwxrwx 1 root root 8 2013-01-08 15:09 /dev/Ketan-8.4 -> ttyUSB12

unbuffer udevadm monitor --environment | grep 'ID_SERIAL='

ACTION!="add", GOTO="persistent_serial_end"
SUBSYSTEM!="tty", GOTO="persistent_serial_end"
KERNEL!="ttyUSB[0-9]*", GOTO="persistent_serial_end"

# This is old 11.10 style: IMPORT="usb_id --export %p"
IMPORT{builtin}="path_id"
ENV{ID_SERIAL}=="04fc_RS232C_to_USB_Adapter"    , SYMLINK="multimeter"                                       , OWNER="jhendrix"
ENV{ID_SERIAL}=="FTDI_FT232R_USB_UART_A800FERY" , SYMLINK="arduinoMega1280-001"       , SYMLINK+="ttyUSB001" , OWNER="jhendrix"
ENV{ID_SERIAL}=="FTDI_FT232R_USB_UART_A900F4EF" , SYMLINK="arduinoMega1280-002"       , SYMLINK+="ttyUSB002" , OWNER="jhendrix"
ENV{ID_SERIAL}=="FTDI_FT232R_USB_UART_A900f3Kr" , SYMLINK="arduinoDuemilanove168-003" , SYMLINK+="ttyUSB003" , OWNER="jhendrix"

LABEL="persistent_serial_end"

unbuffer udevadm monitor --environment | grep 'ID_SERIAL='

/dev/ttyUSB0             # dynamic, assigned by kernel upon plugging the device
/dev/arduinoMega1280-002 # static,  symlink -> ttyUSB0
/dev/ttyUSB002           # static,  symlink -> ttyUSB0 , this is what you are asking for.