I think if you go to the Fonts folder in MacOS X, and for those fonts with
the extension .TTF, you should be able to use them in Windows without
conversion. Also, vice versa.
However, for the "traditional" (old type of) Mac fonts, you will need a
conversion utility.
Of course, I agree that you'll need to bare in mind the copyrights of those
fonts.
Regards,
Edwin Tam
(e-mail address removed)
http://www.vonixx.com