If you have done web development, chances are that you have come across a customer who demands the site to work flawlessly on a variety of browsers; this mainly includes IE and Firefox but sometimes Opera and Safari also make it to the list.
Browsershots is an interesting website that shows you how your webpage looks on several different browsers across all popular operating systems. However, the wait time associated with browsershots is huge. A typical submission to check a website on 3 different browsers took 30 minutes! Of course, one cannot do trial-and-error kind of CSS fixing using this site.
Another option is Browsrcamp which boasts that it can provide instant Mac Safari rendering. However, when I tried it said that Mac services were down.
Other noteworthy mentions could be
But even after going through all the sites I have yet to find a free, fast way of testing your site on a Mac Safari without owning one. One close shot is to just use Safari for Windows. There are very strong chances that if a page is not rendering properly on Safari for Mac OS, it won't work on Safari for Windows either.