if you want a double pinned slider (or need many more pins - for a Photoshop-type gradient selector for instance) you can't really do much better than this plugin, it uses a more OO aproach via the Class.refactor in Mootools More versus some of the other scripts out there which basically totally rewrite the entire Mootools More Slider...and it is only 19 lines!!!
Check it out!!! http://blog.citycrawler.com/?p=74
