How do I keep my contacts list from my old O2 mobile phone to my new vodafone one.?

[treadder]

I am with O2 and have my PAC code to leave them and join maybe vodaphone. I wish to keep my contacts list. Can i save to the old phones memory then put my new sim from vodafone in and copy contacts to that sim then add this new sim to new phone and hay presto. Please tell me its that easy or if not how do I do this.