There are plenty of browsers for Mac computers. Most come with Safari and IE5.2 (which is even more worthless than its Windows counterpart). Firefox should be doing well on Mac, and Opera for Mac is very stable. I also have Camino loaded on mine (I have a Powerbook I keep around for testing purposes). If you want to send me URLs, I'd be happy to take a look at them on various Mac browsers over the weekend.
You can also try www.browsercam.com - they have a trial period you can use for testing. I'd recommend getting a subscription after that, if you do a lot of development.
Safari comes with the Mac and has a great look to it. Unfortunately not all web designers go through the trouble of making their websites totally compatible with Safari. In those cases (maybe 3% to 5% of the sites) I have found that Firefox always works (but does not have that same clean sharp look).
I think that making your site user-friendly for Safari users is a very good idea from a commercial perspective even though it admitedly concerns a small fraction of the cyber-population.
It means your site must work with most browsers, from IE6 to Safari. Those who kick out Mac users (think of most online music stores) are only dumb monkeys who should not do websites at all. Remember: we are on the web and we cannot tell users which OS/browser they have to use.
Michele Bugliaro Goggia, designer SUP in visual communication