Don't know if it's even worth pointing out, but I've noticed that Firefox 3's text resizing goes a step above and beyond in that it also resizes all images relatively as well, meaning that your layouts aren't affected by an increase/decrease in users' font size choice.
This could become a problem if you have images you want to maintain a specific size for any reason, but personally I'm feeling this is a great touch to a great browser to remove a source of potential design headaches. Now if only the majority of users didn't use IE...
Just a random observation, take it as you will.
