[nerv_]

че уж там

<ul class="photos-list" id="photos-list">    
     <li><span><img src="image/1.jpg"></span></li>
     <li><span><img src="image/2.jpg"></span></li>
     <li><span><img src="image/3.jpg"></span></li>
</ul>
<script>
    var elems = document.getElementsByTagName('img');
    var arr = Array.prototype.map.call( elems, function( img ) {
        return img.src;
    });
    alert( arr.join( '\n' ) );
</script>