Currently there is no standard, easy way to move your contacts from Outlook to Address Book that comes with every mac. People new to Mac OS X, especially switchers from PCs or people upgrading from OS 9 often ask the question, and there is no proper answer. Mac OS X Hints has a number of tricks to get around this difficulty.

There are 7 methods mentioned:
1. If you have access to a PC, use a windows program called OutPort
2. Do it via Netscape Communicator
3. Use a program called ABFiller, which is very simple a straightforward
4. Converting to vCards if you have Outlook 2003
5. A more complex trick, using terminal to customise things
6. Importing CSV files to Address Book
7. Importing via Thunderbird

Altogether, these tips should allow you to import contacts into address book in just about every situation.