I'm using Outlook on Windows 2000 at work right now. The following is a way to do it, but it might not be the best way.
If you can't figure out a way to export them all, you can at least go to the "Actions" menu, then "Forward as vCard" and do them one at a time. This will put your contact as a vCard into an e-mail which you can mail to yourself.
I'm not sure how you'd do it for a whole bunch of Contacts - this looks like it will only export a single contact.
I checked Outlook help, and the list of file types it can import/export doesn't look too promising. It definitely says it cannot export vCards (you can only e-mail).
HTH!