We sent our logo off to be redesigned, and the screen shots we got back were from safari. To my horror, our menu system using css was not displaying correctly (it uses the same code as my previous post Opera 7 and <ul>).
How do people test your pages on Safari? I found the brilliant website, where you can download old versions of IE and run them on the same machine, which has been a great help. But apple, is a different story.
I am sure the only answer is to get hold of a apple and test away.
Safari is based on the KHTML rendering engine shared by KDE's Konqueror browser, which runs on Linux. I asked about this recently [webmasterworld.com] and they do appear to be sharing code and updates.
So, along with icapture (which only gives you a static view, so you can't test rollovers or stuff below the fold), you could try a dual boot Windows/Linux and run Konqueror. Cheaper than buying an iMac!