I want/need to as Phase 1 talk to it using the TX/RX lines from the arduino and have the arduino plugged into the computer via USB. that is stage one! if we can get that then i will post Stage/Phase 2 of this project.
From the data sheet, it looks like the logic 0 and logic 1 levels are 0v and 3.3v, but it is not clear which way round. You might need to invert them between the camera and the Arduino using CMOS inverters. If you don't need to invert them, the 3.3v TxData signal from the camera can probably feed the RxData input of the Arduino directly, or use a diode and a pullup resistor to shift the signal from the camera to the Arduino up by 0.6v. You can feed the RxData pin of the camera from a voltage divider attached to the Arduino Tx pin, to drop the 5v to 3.3v.
The main problem you face is that the Arduino Uno can't communicate via both hardware serial and USB in the same sketch, because the USB is driven via the hardware serial port. You'll either have to use one of the solutions I suggested (3 of which involve replacing your Uno for something else), or use software serial. The best solution will be the Leonardo when it is available. If you want to add a UART to your existing Uno, take a look at http://www.sparkfun.com/products/9745 which looks like it already has 3.3v logic levels on the serial Tx and Rx pins.
We have talked to the manufacturer and logic 0 is 3.3V and logic 1 is 0V (if that helps)