I am limited to using jQuery 1.4.2 and jQuery ui 1.8.5 (this is not by choice, please do not ask me to upgrade to latest versions). I have created a slider that shows the cu
The posted solutions are totally workable, but here is another solution that requires no additional plugins and produces this (see fiddle):

Here's how to do it:
Initiate the slider.
For each of the possible values, append a label element with position: absolute (the slider is already position: relative, so the labels will be positioned relative to the slider).
For each label, set the left property to a percentage.
#slider label {
position: absolute;
width: 20px;
margin-top: 20px;
margin-left: -10px;
text-align: center;
}
// A slider with a step of 1
$("#slider").slider({
value: 4,
min: 1,
max: 7,
step: 1
})
.each(function() {
// Add labels to slider whose values
// are specified by min, max
// Get the options for this slider (specified above)
var opt = $(this).data().uiSlider.options;
// Get the number of possible values
var vals = opt.max - opt.min;
// Position the labels
for (var i = 0; i <= vals; i++) {
// Create a new element and position it with percentages
var el = $('').css('left', (i/vals*100) + '%');
// Add the element inside #slider
$("#slider").append(el);
}
});