You can just attach a tooltip-like div that you can append to the handle so it moves along with it. You just have to position it with CSS, like so:
JS
var initialValue = 2012; // initial slider value
var sliderTooltip = function(event, ui) {
var curValue = ui.value || initialValue; // current value (when sliding) or initial value (at start)
var tooltip = '<div class="tooltip"><div class="tooltip-inner">' + curValue + '</div><div class="tooltip-arrow"></div></div>';
$('.ui-slider-handle').html(tooltip); //attach tooltip to the slider handle
}
$("#slider").slider({
value: initialValue,
min: 1955,
max: 2015,
step: 1,
create: sliderTooltip,
slide: sliderTooltip
});
CSS tooltip borrowed from the twitter bootstrap framework
.tooltip {
position: absolute;
z-index: 1020;
display: block;
padding: 5px;
font-size: 11px;
visibility: visible;
margin-top: -2px;
bottom:120%;
margin-left: -2em;
}
.tooltip .tooltip-arrow {
bottom: 0;
left: 50%;
margin-left: -5px;
border-top: 5px solid #000000;
border-right: 5px solid transparent;
border-left: 5px solid transparent;
position: absolute;
width: 0;
height: 0;
}
.tooltip-inner {
max-width: 200px;
padding: 3px 8px;
color: #ffffff;
text-align: center;
text-decoration: none;
background-color: #000000;
-webkit-border-radius: 4px;
-moz-border-radius: 4px;
border-radius: 4px;
}
Demo: http://jsfiddle.net/9qwmX/2/