Thomas Byttebier makes a great case for using text labels over icons. I've been thinking on this of late, largely thanks to Rian van der Merwe. Once you start looking for this issue, you see it everywhere (like the footer of this site).

How often do designers add an icon because it makes perfect sense to them, unknowingly causing confusion? But if we can't agree on a universal icon to represent Save, perhaps sticking with text truly is the best option. Thomas sums it up:

users will avoid interface elements they cannot understand

Give the entire article a read. He includes some poignant examples from apps and sites we all use every day. Mail … a perfect culprit.