improved infinite jQuery marquee with variable pixels/sec, better text width calculation, less resource usage http://jsfiddle.net/ua5rnr1j/

index.html

<div id="slider">
	<div class="edge"></div>
	<ul id="slide-container">
		<li class="slideItem" >
			News happened somewhere&nbsp;&bull;&nbsp;
		</li>
		<li class="slideItem">
			Futhermore, even more news happened elsewhere&nbsp;&bull;&nbsp;
		</li>
		<li class="slideItem">
			It appears that in a foreign country, today news happened&nbsp;&bull;&nbsp;
		</li>
		<li class="slideItem">
			Lorem ipsum stocks are down&nbsp;&bull;&nbsp;
		</li>
		<li class="slideItem">
			Something about China&nbsp;&bull;&nbsp;
		</li>
	</ul>
</div>

slide.js

// http://stackoverflow.com/a/2771544
$.fn.textWidth = function(){
	var html_org = $(this).html();
	var html_calc = '<span>' + html_org + '</span>';
	$(this).html(html_calc);
	var width = $(this).find('span:first').width();
	$(this).html(html_org);
	return width;
};

var marqueeSpeed = 25; // pixels/sec
function tickerSlide() {
	var currentItemWidth = $('.slideItem:first-child').textWidth();
	console.log(currentItemWidth);
	$("#slide-container").animate({marginLeft:-currentItemWidth}, (currentItemWidth / marqueeSpeed) * 1000, 'linear', function(){
		$(this).css({marginLeft:0}).find("li:last").after($(this).find("li:first"));
		tickerSlide();
	});
};

tickerSlide();

style.css

.slider{
    width:100%;
    overflow:hidden;
    position:relative;
    margin:0;
}
.edge{
    left:0;
    right:0;
    top:0;
    bottom:0;
    position:absolute;
    height:100%;
    display:block;
}
.edge:before{
    content:'';
    position:absolute;
    left:0;
    background:-webkit-linear-gradient(left, white 10%, rgba(0,0,0,0) 100%);
    width:25%;
    height:100%;
}
.edge:after{
    content:'';
    position:absolute;
    right:0;
    background:-webkit-linear-gradient(right, white 10%, rgba(0,0,0,0) 100%);
    width:25%;
    height:100%;
}
div#slider > ul{
    background:#ddd;
    overflow:hidden;
    width:1000%;
    margin:0;
}
div#slider > ul > li{
    list-style:none;
    display:inline-block;
    padding:0 50px;
}