Im new here. I want to learn and try to unlock my nokia 8290 and 8390 by myself. After doing some research, I am pretty confuse now.

1. what is a dongle? it seems that it is a must needed for unlocking phone.

2. I saw lots of ppl doing remote unlock for cell phone. How this is possible? If they can calculate the codes by using some software, why i can't do it too?