Ardunio as full USB-Serial TTL Convter With RTS

Using Arduino Interfacing w/ Software on the Computer
1

Hi,Can Anyone help me out with the code to use a Freetronics arduino as a USB-Serial converter for a project I'm doing,All I can find is Data TX and RX but I need ALL the functions and especially RTS

2

Which board?

3

Wouldn't it be much simpler to get an off-the-shelf USB-TTL converter with the required functionality?

...R