Take your icon game to the next level. Check out Fonticons, from the maker of Font Awesome.
             

fa-calendar-o · Unicode: f133 · Created: v3.1 · Categories: Web Application Icons

After you get up and running, you can place Font Awesome icons just about anywhere with the <i> tag:

fa-calendar-o
<i class="fa fa-calendar-o"></i>

Looking for more? Check out the examples.