Don't know if this site has been mentioned before, but anyone who wants to save a few pennies and put their own interface/cable together can buy stuff here:
http://www.andywhittaker.com/ecu/obdii_hardware.htm
I've just ordered the board and OBD connector, the rest of the bits are items commonly found at my work
http://www.andywhittaker.com/ecu/obdii_hardware.htm
I've just ordered the board and OBD connector, the rest of the bits are items commonly found at my work