There are 5 previous versions of this script.
// ==UserScript==
// @name Last.fm - Fire.fm Links
// @version 1.0b
// @namespace none
// @description Extension for Fire.fm users that replaces "lastfm://" with "firefm://station/".
// @author s!n
// @contact http://last.fm/user/-sin
// @licence Creative Commons
// @include http://www.last.fm*
// @include http://www.lastfm.*
// @include http://cn.last.fm*
// ==/UserScript==
var allLinks, thisLink;
xpath = '//a[contains(@href, "lastfm://")]';
allLinks = document.evaluate(xpath,document, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
for (var i = 0; i < allLinks.snapshotLength; i++) {
thisLink = allLinks.snapshotItem(i);
thisLink.href = thisLink.href.replace(/^lastfm:\/\/globaltags\//,"firefm://station/tag/");
thisLink.href = thisLink.href.replace(/^lastfm:\/\//,"firefm://station/");
}