em units on CSS

It's kind of shocking to see the (low) number of people who have em sizings in CSS's. They call them hard and messy, but they're really a path to create usable pages, being the best practice to use them, specially if you want your site to be well readable in every kind of screen, browser and specially resolution.

If you're curious about this issue, I recommend you to read this post and grovel for more.