Ok i'll try once again.
1) It has nothing to do with Android !
2) we have two different problems here to solve .
Problem #1 : I have a Nokia s60/s40 phone, i'm going to get a Android powered device which i'm going to use and it's going to be my only device after that .
Solution to problem #1 ( in detail somebody already posted it to this forum and bunch of other forums ) but basically what you need to do EXPORT your contacts from Nokia to csv file and then Import them to gmail contacts. After you connect your android phone to the network - your contacts will be there. Estimate time to do that - 20 minutes, difficulty level 0.
Problem #2 : I have Nokia s60/s40 device and going to get Android device. I'm going to carry both of them all the time. How to keep my contact in sync.
Solution: in order archive this goal you need live sync your Nokia contacts to Gmail contacts. This can be done by third party utility similar to Goosync ( runs about 19 pounds a year). Or by writing your own utility which will sync it google contacts. Same thing can be also archived by phone-to-phone sync, which in my opinion a strange solution, because it would involve development on both platforms. And writing for S60 is no picnic from what i've heard.