John Gruber linked to an article about the text-rendering:optimizeLegibility CSS property today and as he said, news to me. I’ve built a quick Safari extension to enable it by default in Safari (Firefox already does this). So, without further ado:
Optimize Legibility is a simple Safari extension that injects a single CSS attribute (text-rendering:optimizeLegibility) into every page. This will improve kerning and ligatures in text.
Update: 1.0.2 adds an icon and reverts the CSS to matching body rather than wildcard. Should improve performance (although it won’t be noticeably faster on any modern machine).