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

fa-foursquare · Unicode: f180 · Created: v3.2 · Categories: Brand Icons

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

fa-foursquare
<i class="fa fa-foursquare"></i>

Looking for more? Check out the examples.