gistfile1.js

// HOWTO: load LABjs itself dynamically!
// inline this code in your page to load LABjs itself dynamically, if you're so inclined.

(function (global, oDOC, handler) {
    var head = oDOC.head || oDOC.getElementsByTagName("head");

    function LABjsLoaded() {
        // do cool stuff with $LAB here
    }

    // loading code borrowed directly from LABjs itself
    setTimeout(function () {
        if ("item" in head) { // check if ref is still a live node list
            if (!head[0]) { // append_to node not yet ready
                setTimeout(arguments.callee, 25);
                return;
            }
            head = head[0]; // reassign from live node list ref to pure node ref -- avoids nasty IE bug where changes to DOM invalidate live node lists
        }
        var scriptElem = oDOC.createElement("script"),
            scriptdone = false;
        scriptElem.onload = scriptElem.onreadystatechange = function () {
            if ((scriptElem.readyState && scriptElem.readyState !== "complete" && scriptElem.readyState !== "loaded") || scriptdone) {
                return false;
            }
            scriptElem.onload = scriptElem.onreadystatechange = null;
            scriptdone = true;
            LABjsLoaded();
        };
        scriptElem.src = "/path/to/LAB.js";
        head.insertBefore(scriptElem, head.firstChild);
    }, 0);

    // required: shim for FF <= 3.5 not having document.readyState
    if (oDOC.readyState == null && oDOC.addEventListener) {
        oDOC.readyState = "loading";
        oDOC.addEventListener("DOMContentLoaded", handler = function () {
            oDOC.removeEventListener("DOMContentLoaded", handler, false);
            oDOC.readyState = "complete";
        }, false);
    }
})(window, document);

gistfile2.js

// compressed more suitable for inlining
// ~640b before gzip

(function(g,b,d){var c=b.head||b.getElementsByTagName("head"),D="readyState",E="onreadystatechange",F="DOMContentLoaded",G="addEventListener",H=setTimeout;
function f(){
   // $LAB stuff here
}
H(function(){if("item"in c){if(!c[0]){H(arguments.callee,25);return}c=c[0]}var a=b.createElement("script"),e=false;a.onload=a[E]=function(){if((a[D]&&a[D]!=="complete"&&a[D]!=="loaded")||e){return false}a.onload=a[E]=null;e=true;f()};

a.src="/path/to/LAB.js";

c.insertBefore(a,c.firstChild)},0);if(b[D]==null&&b[G]){b[D]="loading";b[G](F,d=function(){b.removeEventListener(F,d,false);b[D]="complete"},false)}})(this,document);

@tobie -- it's to address an older IE quirk/bug where the [0] element is not yet set, and if you capture a ref to it too early, when it's made available, your ref will be invalid.

Heh. Deserves a comment, don't you think?