Javascript optimisation - while (See related posts)

Using as a benchmark the task of iterating over a live collection produced by getElementsByTagName. IE/Win, Gecko and Safari all agree as to the fastest means:

var i = 0, el, els = document.getElementsByTagName(nodeName);
while (el = els[i++]) {
    // [...]
}

Using a while loop and storing the live collection in a variable is the quickest technique in all of these browsers.