Getting contacts off your old mobile phone and onto the iPhone may or may not be a straightforward process. If you already have your contacts stored neatly in Outlook (Windows), Address Book (Mac) or a Yahoo!/Gmail Address Book (Mac/Windows), the process is as simple as syncing via iTunes. If all you have is a set of contacts stored on an old Nokia 6300, however, the process is a bit more involved.
Edit: To complicate things I have no budget (so I must rule out paid for Apps)
Edit: I don't live in America, so suggestions in other forums saying "Just take it to AT&T" don't apply to me