I've created a custom style sheet for Safari (which also works in all other major browsers) that enhances the results listings from major search engines -- it numbers all the results, including any paid advertising, which makes it easier to see how your site ranks while checking out various search results. (It also highlights links and images that use the "nofollow" attribute.)
To use this custom sheet in Safari, save the style sheet locally somewhere; name it something like Custom Style Sheet.css. In Safari, open preferences, click Advanced, then click the drop-down next to Style Sheet and navigate to the Custom Style Sheet.css you just saved. You can read more about this custom style sheet in this entry on my blog -- I think this is a big upgrade for all web/SEO people using Safari.
[robg adds: I haven't tested this one.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20081003085631297