Built a function to turn a text field into an icon picker for FontAwesome:

<link rel="stylesheet" type="text/css" href="/library/js/fontIconPicker/2.0.1-cs/css/jquery.fonticonpicker.css" />
<link rel="stylesheet" type="text/css" href="/library/js/fontIconPicker/2.0.1-cs//themes/grey-theme/jquery.fonticonpicker.grey.min.css" />
<script type="text/javascript" src="/library/headscripts.js"></script>
<script>includeLatestJQuery('my_tool_name');</script>
<script type="text/javascript" src="/library/js/fontIconPicker/2.0.1-cs/jquery.fonticonpicker.min.js"></script>

<input type="text" id="icon_input" name="icon_input" />

<script>fontawesome_icon_picker('#icon_input');</script>

Based on: http://codeb.it/fonticonpicker/