If an Arduino "talks" to another device via serial connection, you can see what the Arduino transmits via the serial monitor. My question is if another device responds, would you see it in the same serial monitor window? (of the Arduino IDE). Thanks, I owe you a beer. 
No.
Only if you print what the device sends back. Basically, you would end up returning the received data. Send data->Get reply->Re-send data Since you know that you can see the data when sending (Serial.print) you would be able to see the returned data, but you may need to then account for an infinite loop.
Hey thanks a lot!
I was having trouble with this when trying to interface an Arduino with a cellphone. I will try and get the phone to run in hyperterminal to make sure the commands work, and then program them into the Arduino.
Thanks again!
If an Arduino "talks" to another device via serial connection, you can see what the Arduino transmits via the serial monitor.
In this case, the "other device" is your PC. The serial monitor doesn't show you what would happen between the Arduino and another device.