Jquery-throbbo is a project mainly written in JavaScript, it's free.
Jquery throbber (aka spinner aka loader)
h1. Throbbo
Throbbo is a jQuery plugin that makes is easy to display a throbber (aka spinner) while loading.
h2. Usage
Show throbber as an overlay in #foo. Throbber will show for 2 sec.
$('#foo').throbbo({duration: 2000});
Show throbber as an inline image inserted before #bar.
$('#bar').throbbo({duration: 2000, mode:'insertBefore'});
"Check it out i action here":http://afartinspace.com/lab/jquery-throbbo/demo.html