Designers have their bag of tricks including the ability to custom-design icons, but this can be time consuming pixel pushing work that a lean startup just cannot afford. And some companies have invested in custom icons because of the critical nature of the icons to their product perhaps including highly domain-specific glyphs.
But for the rest of us, sometimes we just want quick, dirty, nice, and awesome.
Which brings us to … Font Awesome!
http://fortawesome.github.io/Font-Awesome/cheatsheet/
Basically you can have at it under the GPL with this set of clean, concise, internationally recognizable icons which have been conveniently and cleverly rendered as a font. So much like the anemic webdings of yore, the FontAwesome icon set is really a sweet “font” of icons.