Optimize JQuery/JavaScript Link Checker
Firstly, for...in is used to enumerate over object properties, not to iterate through arrays.  You should use a traditional for loop for this.

Secondly, you could probably refine your console logging portion a bit. It may not have any impact to application performance, but it would make your console look prettier.

$('body').on('click', '#logReport', function() {
    var i, j, k, l;

    console.group("Live Links:");
    for (i=0, j=liveLinks.length; i&lt;j; i++) {
        console.log(liveLinks[i]);
    }
    console.groupEnd();
    console.group("Dead Links:");
    for (k=0, l=deadLinks.length; k&lt;l; k++) {
        console.log(deadLinks[k]);
    }
    console.groupEnd();
});


As far as I know, this works for both Google Chrome and Mozilla Firefox (FireBug).  See here for more information.