Hey guys, I did something similar but based off the styles of the jQuery UI slider plugin. I found while these types of standalone plugins looked okay, they were frustrating to customise or even to make them look PERFECT.
This looks great! One minor suggestion: make the toggle button non selectable for dragging. http://jsfiddle.net/SWqw3/ show's a basic way of doing this.
One thing - I know the intent is that they can be easily customized, but it might be nice to have smaller options out of the box. I think I've been spoiled by Twitter Bootstrap, though, where they have a few preset sizes. My first thought was that they looked a little large.
It looks like the primary function of the button is to alter something on the page via the toggles function, but I guess you could check if it had the active class or not.
You also might want to `return this.each` so calls can be chained.
All of this is covered here: http://docs.jquery.com/Plugins/Authoring