Hi!
I could not find this answer on the internet, so as I have managed to solve my problem, I want to share it with you. When you want to print a photo from your D80, make sure you change some settings!
Problem:
If you use your USB cable to copy your photos from the camera to your laptop, you will see your PictBridge printer is not identified by your camera - instead, "PC" sign is displayed on the top display.
Solution:
Before plugging camera to the printer, go to settings and change the type of USB Cable from M to P (from Mass Storage to PTP).
Now you can plug in your camera and print in a second!