I have a nokia N73 music edition mobile.... My doubt is --->
will this phone work at North america /Europe with a new sim-connection taken from there ?
yes. it should work. but if you are planning for long stay there (1yr or higher), better get contract based service and you will have some superb phones to pick.
Based on this your phone should work there. No personal experience though. (Based on feedback from few team mates, if it is for long duration its a good idea to get a high end contract phone at economic rates)