Hi, for "saving"

USB Port, it's possible to connect Arduino directly at the COM1 of JaguarBoard.
It' s necessary 3 resistences :
nr2 of 820 ohm
nr 1 of 3.3Kohm
the GND of Arduino directly connect to PIN1 of JaguarBoard.
RX of Arduino directly connect to PIN2 of JaguarBoard.
TX : connect nr2 820ohm in serial and after connect the GND with 3,3 khom , connect the node to PIN3 of JaguarBoard.
Example in C# working now in my project
_serialPort = new SerialPort(
mySerialSettings.PortName, // COM1
mySerialSettings.BaudRate, // 9600
mySerialSettings.Parity, // Parity.None
mySerialSettings.DataBits, // 8
mySerialSettings.StopBits); // StopBits.One
_serialPort.ErrorReceived += new SerialErrorReceivedEventHandler(ErrorReceivedHandler);
_serialPort.DataReceived += new SerialDataReceivedEventHandler(NewSerialDataRecieved);
_serialPort.Open();