[thekungfuman]

Does using the <i> tag have any negative effect on the semantic markup of a page? I see that it doesn't impact screen-readers but what about if someone is trying to parse your HTML?

[fortawesome]

Should also work just fine with the <span> tag. <i> is just shorter. I went with the same method Twitter Bootstrap 2.0 is using for their fixed-size icons: http://twitter.github.com/bootstrap/base-css.html#icons