kmlTreeSprites uses several images provided by Mark James as part of the Silk icon set. See ./silk for more details.

checkbox.png and radiobutton.png are modified from this tutorial:
http://www.filamentgroup.com/lab/accessible_custom_designed_checkbox_radio_button_inputs_styled_css_jquery/
The accompanying source code is for progressive enhancement of form inputs is available under both GPL and MIT licenses here:
http://www.filamentgroup.com/examples/customInput/customInput.jquery.js