KidsKilla

var q = 0, urls = [];
innerHTML.replace(/\s+/, ' ').replace(/(?:\r|\n|\s)+/, ' ').replace(
    /<img(?:.+?)?src=("|')(.+?)\1(?:.+?)?>/i, 
    function(mtch, q, url) {
        urls[q++] = url;
    }
);
alert('Картинок - '+q);