The following is the FireGestures script for downloading a Nico Nico Douga link by NicoFox:

var url = FireGestures.getLinkURL();
url = url.replace(/^http:\/\/ime\.nu\/(.*)$/, 'http://$1');
url = url.replace(/^http:\/\/www\.flog\.jp\/w\.php\/(.*)$/, '$1');
if (url.match(/^http:\/\/(www|tw|de|es)\.nicovideo\.jp\/watch\/([a-z]{0,2}[0-9]+)$/) && gBrowser) {
  nicofox.goDownload(url);
}