Dev/Grow

Thanks! It took a little while but I think I figured it out. The only problem is that this is not part of the core plugin (unless a lot of people request it), so if I release an update and you upgrade automatically through WordPress, it will override the settings.

Replace your sharebar.js with the following and edit the value var d = 2000; with whatever height from the bottom of the page you want to stop the Sharebar. This isn't automatic as it depends on the size of your footer.

sharebar.js:

/*
 *  ShareBar - Creates a dynamic, vertical sharing bar to the left of a WordPress post and hides it if browser window is too small
 *  Copyright 2010 Monjurul Dolon, http://mdolon.com/
 *  Released under the MIT, BSD, and GPL Licenses.
 *  More information: http://devgrow.com/sharebar
 */
jQuery.fn.sharebar = function(options) {
	var defaults = {horizontal: true, minwidth: 1000, position: 'left', leftOffset: 20, rightOffset: 10};
	var opts = jQuery.extend(defaults, options); var o = jQuery.meta ? jQuery.extend({}, opts, jQueryjQuery.data()) : opts;

	var w = jQuery(window).width();
	var sharebar = jQuery('#sharebar');
	var sharebarx = jQuery('#sharebarx');
	var parent = jQuery(sharebar).parent().width();
	var sw = jQuery(sharebar).width();
	var start = sharebar_init();
	var st = jQuery(sharebar).offset().top;

	function sharebar_init(){
		if (o.position == 'left') jQuery(sharebar).css('marginLeft',(0-sw-o.leftOffset));
		else {
			jQuery(sharebar).css('marginLeft',(parent+o.rightOffset));
		}
		if(w < o.width && o.horizontal) jQuery(sharebarx).slideDown();
		else jQuery(sharebar).fadeIn();
		jQuery.event.add(window, "scroll", sharebar_scroll);
		jQuery.event.add(window, "resize", sharebar_resize);
		return jQuery(sharebar).offset().top;
	}
	function sharebar_resize() {
		var w = jQuery(window).width();
		if(w<o.minwidth){
			jQuery(sharebar).fadeOut();
			if(o.horizontal) jQuery(sharebarx).slideDown();
		}else{
			jQuery(sharebar).fadeIn();
			if(o.horizontal) jQuery(sharebarx).slideUp();
		}
	}
	function sharebar_scroll() {
		var p = jQuery(window).scrollTop();
		var w = jQuery(window).width();
		var d = 2000; // Distance from bottom in pixels for when to stop scrolling
		var tp = p + jQuery(sharebar).height();
		var h = jQuery(document).height();
		if(tp < (h-d)){
			jQuery(sharebar).css('position',((p+10)>start) ? 'fixed' : 'absolute');
			jQuery(sharebar).css('top',((p+10)>start) ? '10px' : '');
		}else{
			jQuery(sharebar).css('position','absolute');
			jQuery(sharebar).css('top',h-d-st-jQuery(sharebar).height());
		}
	}

};