I know on the PC it can be used as a modem, but what about with a Mac laptop.

I have never had any other issues with S60 devices, except with the initial firmware versions of the 5800XM, which is what has concerned me about the i8910HD.

With joikuspot (http://www.joiku.com/index.php?action=products&mode=productDetails&product_id=310) it's easy as 1-2-4.